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 A101087 #10 May 07 2025 17:20:00 %S A101087 4,6,7,8,9,10,11,15,17,19,23,25,26,29,31,47,53,65,67,71,73,113,127, %T A101087 199,257,349,421,433,449,691,761,823,991,1237,1277,1399,1531,1571, %U A101087 3461,3697,4933,6199,7351 %N A101087 Indices of prime values of A077020 (also A001607). %C A101087 There are only 9 composite numbers in the entire sequence, namely: 4, 6, 8, 9, 10, 15, 25, 26 and 65. %C A101087 If we are prepared to accept probable primes, then the sequence continues as follows: 9551, 9719, 11681, 12037, 14629, 14951, 19079, 20327, 22549, 30517, 51511, 52813, 60923, 73943, 79687, 91249, 115321, 117017, 169493, 172411, 174413, 237053, 285631, 318751, 327433. - _David Broadhurst_, May 23 2007 %H A101087 G. P. Michon, <a href="http://www.numericana.com/answer/numbers.htm#m">Never Back to -1</a>. %Y A101087 Cf. A001607, A077020 (all values) and A101088 (prime values only). Similar to A001605 (Fibonacci primes), A000043 (Mersenne primes), A096650 (Pell primes), etc. %K A101087 nonn %O A101087 1,1 %A A101087 _Gerard P. Michon_, Dec 01 2004