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 A177748 #22 Aug 04 2024 17:59:41
%S A177748 3,257,337,4423,4919,30431,66841,514271,14490383,231234569,325923613,
%T A177748 640085473,1600993259,7180164577,8069913503,86933359951,284331217637,
%U A177748 1128352801153,1209935587291,2454267258251,2945783287813
%N A177748 First primes of record chains of consecutive primes such that all of them are evil (A027699).
%C A177748 The first lengths of such chains of primes are: 2, 3, 5, 7, 8, 12, 16, ..., cf. A177801.
%e A177748 257 is the first evil prime followed by two consecutive primes (263,269) which are also evil. Thus it is record length 3.
%o A177748 (PARI) {l=0;sp=0;r=0; forprime( p=1, default(primelimit), if( norml2(binary(p))%2, l>r & !print1(sp", ") & r=l; l & l=0, l || sp=p; l++))} \\ _M. F. Hasler_, Dec 12 2010
%Y A177748 Cf. A001969, A000069, A027697, A027699, A177798 (odious version), A177801.
%K A177748 nonn,base,more
%O A177748 1,1
%A A177748 _Vladimir Shevelev_, Dec 12 2010
%E A177748 More terms from _D. S. McNeil_, Dec 12 2010
%E A177748 a(18)-a(21) from _Amiram Eldar_, Dec 09 2020