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 A251553 #14 Aug 06 2021 00:46:33 %S A251553 3,5,7,10,12,17,19,21,24,26,28,31,33,37,39,42,44,47,49,52,55,57,59,64, %T A251553 66,69,71,73,75,78,81,83,85,90,92,95,97,100,102,104,107,109,111,113, %U A251553 115,117,120,123,129,131,133,136,138,140,143,145,149,152,155,157,159,162,164,169,171,173,176,178 %N A251553 Numbers k such that A098550(k) is a multiple of 3. %C A251553 This sequence is now known to be infinite. %H A251553 Chai Wah Wu, <a href="/A251553/b251553.txt">Table of n, a(n) for n = 1..10000</a> %o A251553 (Haskell) %o A251553 a251553 n = a251553_list !! (n-1) %o A251553 a251553_list = filter ((== 0) . flip mod 3 . a098550) [1..] %o A251553 -- _Reinhard Zumkeller_, Dec 19 2014 %Y A251553 Cf. A098550. %Y A251553 Second row of array A251716. %K A251553 nonn %O A251553 1,1 %A A251553 _N. J. A. Sloane_, Dec 18 2014