Does this help you. I attacked the problem from the other end ...
If 1 = a, then here's the 6 letter words that start and begin with the same letter not including 'a':
chemic,cleric,clinic,cosmic,critic,cyclic,defend,depend,dogged,dogood,edible,emerge,emigre,empire,encode,encore,endure,engine,enrobe,ensure,entice,entire,enzyme,europe,evince,evolve,excise,excite,excuse,exhume,expire,expose,giving,lentil,lintel,medium,museum,muslim,neuron,noggin,notion,overdo,pickup,rector,render,renter,rigger,rigour,ringer,rioter,ripper,robber,rocker,roller,roster,router,rubber,rudder,rumour,runner,shirts,shorts,sights,slings,smokes,spoils,spokes,sports,stress,stylus,sweeps,sweets,swords,theist,thirst,thrift,thrust,ticket,tidbit,titbit,toilet,tumult,turret,typist,willow,window,winnow
and here's the list of those with the middle 2 letters the same:
bellow,better,bidder,billet,billow,bitter,bloods,bloody,bobbin,bobble,boffin,boggle,bonnet,bonnie,borrow,bottle,bottom,breech,breeze,brooch,brooms,bubble,buffer,buffet,bugger,bullet,burrow,butter,button,buzzer,cheese,choose,cobble,coffee,coffer,coffin,collie,commit,common,copper,cosset,cotton,cuddle,cutter,cuttle,differ,digger,dimmer,dinner,dogged,fellow,ferret,fetter,fibber,fiddle,filler,fillet,fitter,fizzle,fleece,floors,fodder,follow,fossil,freeze,fuddle,funnel,furrow,gibber,gibbet,gibbon,giggle,gobbet,gobble,gossip,greens,groove,gullet,gulley,gunner,gutter,guzzle,hiccup,hippie,hobble,holler,hollow,hopper,horrid,horror,huddle,jitter,jogger,judder,juggle,kennel,kettle,killer,kipper,kitten,lessee,lessen,lesson,lessor,letter,linnet,lissom,litter,little,logger,lopper,lubber,meddle,mellow,middle,miller,minnow,mirror,missus,mitten,muddle,muffin,muffle,mugger,mussel,mutter,mutton,muzzle,nettle,nibble,niggle,nipple,noggin,nozzle,nugget,nuzzle,pebble,peddle,pellet,pepper,pillow,pippin,pollen,possum,potter,puddle,puffin,pulley,pummel,puppet,putter,puzzle,redden,ribbon,riddle,riffle,rigger,ripper,ripple,robber,roller,rotten,rubber,rubble,rudder,ruffle,rugged,runner,seller,settee,setter,settle,simmer,sinner,sipper,sitter,sizzle,sleeve,smooth,sneeze,snooze,sonnet,sorrow,speech,stooge,sudden,suffer,suffix,sullen,summer,summit,summon,supper,supple,supply,surrey,sweeps,sweets,teller,terror,tiller,tissue,titter,toddle,toffee,toggle,topple,tossup,totter,troops,tunnel,turret,tussle,vessel,volley,welled,wheeze,wiggle,willow,winner,winnow,witter,wobble,yellow,yuppie,zipper
... and then repeating that if 1 = i instead:
agenda,alaska,alpaca,amoeba,angola,angora,armada,asthma,aurora,azalea,baobab,cognac,defend,demand,depend,dogged,dogood,efface,elapse,emerge,enable,encase,encode,encore,endure,engage,enrage,enrobe,ensure,enzyme,equate,escape,estate,europe,evolve,excuse,exhale,exhume,expose,haunch,health,hearth,hurrah,laurel,lawful,lethal,magnum,museum,neaten,neuron,norman,overdo,preamp,rafter,ranger,ranker,ranter,raptor,rasher,raster,reader,reaper,rector,render,renter,robber,rocker,roller,roster,router,rubber,rudder,rumour,runner,shorts,smalls,smokes,snakes,spaces,spokes,sports,stands,states,status,steams,stress,stylus,sweats,sweeps,sweets,swords,tablet,talent,target,teapot,tenant,threat,throat,thrust,thwart,truant,tumult,turret,tyrant,wallow
babble,baffle,ballad,ballet,ballot,banner,barrel,barren,barrow,batten,batter,battle,beggar,bellow,better,bloods,bloody,bobble,boggle,bonnet,borrow,bottle,bottom,breech,breeze,brooch,brooms,bubble,buffer,buffet,bugger,bullet,burrow,butter,button,buzzer,caller,callow,cannon,carrot,cellar,cheese,choose,cobble,coffee,coffer,collar,common,copper,corral,cosset,cotton,cuddle,cutter,cuttle,dabble,dagger,dapple,dazzle,dogged,dollar,faggot,faller,fatten,fellow,ferret,fetter,fleece,floors,fodder,follow,freeze,fuddle,funnel,furrow,gabble,gaggle,galley,gallon,gallop,gannet,garret,gobbet,gobble,greens,groove,guffaw,gullet,gulley,gunner,gutter,guzzle,haggle,hallow,hammer,happen,harrow,hatter,hobble,holler,hollow,hopper,horror,huddle,hurrah,jabber,jagged,jogger,judder,juggle,kennel,kettle,ladder,lessee,lessen,lesson,lessor,letter,logger,lopper,lubber,madden,maggot,mallet,mammal,manner,mapper,marrow,matter,meddle,mellow,muddle,muffle,mugger,mullah,mussel,mutter,mutton,muzzle,narrow,nettle,nozzle,nugget,nuzzle,paddle,pallet,parrot,passer,patten,patter,pebble,peddle,pellet,pepper,pollen,possum,potter,puddle,pulley,pummel,puppet,putter,puzzle,raffle,ragged,rattle,redden,robber,roller,rotten,rubber,rubble,rudder,ruffle,rugged,runner,sabbat,sadden,saddle,sapper,seller,settee,setter,settle,sleeve,smooth,sneeze,snooze,sonnet,sorrow,speech,stooge,sudden,suffer,sullen,summer,summon,supper,supple,supply,surrey,sweeps,sweets,tanner,tassel,tattoo,teller,terror,toddle,toffee,toggle,topple,tossup,totter,troops,tunnel,turret,tussle,valley,vassal,vessel,volley,waddle,waffle,waggle,wallet,wallow,warren,welled,wheeze,wobble,yellow