A177949 First string of 43 consecutive composite numbers.

15684, 15685, 15686, 15687, 15688, 15689, 15690, 15691, 15692, 15693, 15694, 15695, 15696, 15697, 15698, 15699, 15700, 15701, 15702, 15703, 15704, 15705, 15706, 15707, 15708, 15709, 15710, 15711, 15712, 15713, 15714, 15715, 15716, 15717, 15718, 15719, 15720, 15721, 15722, 15723, 15724, 15725, 15726

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, May 15 2010

Keywords

• nonn
• fini
• full

Crossrefs

Cf. A051884

Programs

Maple

P:= select(isprime, [seq(i,i=3..20000,2)]):
G:= P[2..-1]-P[1..-2]:
i0:= ListTools:-SelectFirst(j -> G[j]>=42, [$1..nops(G)]):
$ P[i0]+1 .. P[i0]+43; # Robert Israel, Jul 05 2017

Mathematica

rPrimeNext[n_]:=Module[{k},k=n+1;While[PrimeQ[k]||GCD[n,k]!=1,k++ ];k]; a=1;lst={a};Do[AppendTo[lst,a=rPrimeNext[a]],{n,0,2*7!}];lst1=lst; q=41;lst={};Do[If[lst1[[n+q]]-lst1[[n]]==q,AppendTo[lst,lst1[[n]]]],{n,0,Length[lst1]-q}];lst; a=FromDigits[lst];Table[n,{n,a,a+q}]

Extensions

Edited by Robert Israel, Jul 05 2017