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 A091021 #14 Jan 03 2025 17:47:25 %S A091021 2,11,13,47,127,131,139,167,227,229,419,421,8419,15391,18503,23053, %T A091021 31333,32119,642049,771769,1240081,2545453,2951341,9677999,11390809, %U A091021 22436899,33056171,63701437,71298761,465462769,989883217,1490754379,1775394377,1775394389 %N A091021 Primes p=prime(k) such that in binary representation k is a substring of p. %F A091021 a(n) = A000040(A091020(n)). %F A091021 A091020(n) = A049084(a(n)). %e A091021 229 = A000040(50): 50->110010, 229->11100101 = 1'110010'1, therefore 229 is a term. %o A091021 (Python) %o A091021 from sympy import primerange %o A091021 [print(i, end=', ') for n, i in enumerate(primerange(1, 10**7)) if bin(n+1)[2:] in bin(i)[2:]]; # _Nicholas Stefan Georgescu_, Jan 03 2025 %Y A091021 Cf. A007088, A004676. %K A091021 nonn,base %O A091021 1,1 %A A091021 _Reinhard Zumkeller_, Dec 14 2003 %E A091021 a(22)-a(32) from _Donovan Johnson_, May 03 2010 %E A091021 a(33)-a(34) from _Donovan Johnson_, May 08 2012