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 A309430 #8 Aug 01 2019 10:48:05 %S A309430 1,2,2,3,4,4,5,6,6,7,7,8,9,9,10,10,11,11,12,13,13,13,14,14,15,16,16, %T A309430 17,17,18,19,19,19,20,20,21,21,22,23,23,24,24,25,25,26,26,26,27,27,28, %U A309430 29,29,30,30,31,31,32,33,33,33,34,34,35,36,36,37,37,38,38,38,39,39,40,41,41,41,42,42,43,44,44 %N A309430 a(n) = a(n-a(n-1)) + a(n-a(n-4)), with a(n) = ceiling(2*n/3) for n <= 7. %C A309430 A slow solution to Hofstadter V recurrence. %C A309430 Numbers k such that a(k) < A063882(k) are 1654, 1721, 1925, ... %F A309430 a(n+1) - a(n) = 0 or 1 for all n >= 1. %o A309430 (PARI) q=vector(100); for(n=1, 7, q[n]=ceil(2*n/3));for(n=8, #q, q[n]=q[n-q[n-1]] +q[n-q[n-4]]); q %Y A309430 Cf. A063882, A317686, A319020. %K A309430 nonn,easy %O A309430 1,2 %A A309430 _Altug Alkan_, Aug 01 2019