This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A270311 #17 Mar 07 2024 15:40:40 %S A270311 34,35,42,43,53,54,61,62,68,69,80,81,82,83,101,102,106,107,115,116, %T A270311 125,126,127,128,138,139,141,142,145,146,154,155,157,158,172,173,175, %U A270311 176,177,178,191,192,193,194,204,205,222,223,233,234,258,259,260,266,267,269,270,279,280,289,290,306,307 %N A270311 Indices of primes ending with the same decimal digit as the previous or next prime. %H A270311 Harvey P. Dale, <a href="/A270311/b270311.txt">Table of n, a(n) for n = 1..1000</a> %t A270311 Select[Range@ 307, Function[k, Or[k == Mod[NextPrime@ Prime@ #, 10], k == Mod[NextPrime[Prime@ #, -1], 10]]]@ Mod[Prime@ #, 10] &] (* _Michael De Vlieger_, Mar 15 2016 *) %t A270311 PrimePi/@Select[Partition[Prime[Range[350]],3,1],Mod[#[[2]],10]==Mod[#[[1]],10]||Mod[#[[2]],10]==Mod[#[[3]],10]&][[;;,2]] (* _Harvey P. Dale_, Mar 07 2024 *) %Y A270311 Cf. A270310. %K A270311 nonn,base %O A270311 1,1 %A A270311 _Francois Alcover_, Mar 15 2016 %E A270311 More terms from _Michael De Vlieger_, Mar 15 2016