cp's OEIS Frontend

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.

A177798 First primes of record chains of consecutive primes such that all of them are odious (A027697).

This page as a plain text file.
%I A177798 #16 Jun 02 2025 02:56:17
%S A177798 2,7,167,199,6271,12227,168713,579907,5937157,6829751,8059943,
%T A177798 66858173,167857663,661416709,2322857987,12012698381,14641587607,
%U A177798 26304771553,49671709081,1244930533403,1922085626009
%N A177798 First primes of record chains of consecutive primes such that all of them are odious (A027697).
%C A177798 The corresponding record lengths are: 1,3,6,9,11,15, etc. (A177800).
%o A177798 (PARI) back(p,k)=while(k--,p=precprime(p-1));precprime(p-1)
%o A177798 r=s=0;forprime(p=2,1e9,if(hammingweight(p)%2,s++,if(s>r,r=s;print1(back(p,r)", "));s=0)) \\ _Charles R Greathouse IV_, Mar 29 2013
%Y A177798 Cf. A177748 (evil version), A000069, A001969, A027697, A027699, A177800.
%K A177798 nonn,base,more
%O A177798 1,1
%A A177798 _Vladimir Shevelev_, Dec 12 2010
%E A177798 More terms from _D. S. McNeil_, Dec 12 2010
%E A177798 a(20)-a(21) from _Amiram Eldar_, Dec 09 2020