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 A305151 #11 May 26 2018 17:28:36 %S A305151 0,0,0,3,0,0,4,10,5,7,14,0,17,7,0,25,0,0,17,0,0,15,33,11,34,0,0,19,13, %T A305151 35,41,56,0,31,0,11,31,60,57,27,0,0,76,27,0,31,53,0,85,0,17,37,0,79, %U A305151 91,74,0,85,25,0,40,87,100,119,93,0,111,0,117,109,94,83,97,31,17,51,102,0 %N A305151 a(n) = (2n+1) - A294673(n), the amount by which A294673 is less than the maximum possible for n. %C A305151 Motivation: A294673(n), which is always <= 2n+1, equals n in most cases. This sequence abstracts out that commonality to leave a cleaner signal. %o A305151 (PARI) a(n) = (2*n+1) - znorder(Mod(if(n%2, 2, -2), 4*n+3)); \\ _Michel Marcus_, May 26 2018 %Y A305151 Cf. A294673. %K A305151 nonn %O A305151 0,4 %A A305151 _P. Michael Hutchins_, May 26 2018