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 A298415 #4 Feb 11 2018 10:52:25 %S A298415 1,1,1,4,7,16,34,70,145,292,598,1198,2428,4858,9784,19570,39283,78568, %T A298415 157426,314854,630304,1260610,2522416,5044834,10092094,20184190, %U A298415 40373236,80746474,161502730,323005462,646030492,1292060986,2584161253,5168322508,10336723582 %N A298415 a(n) = a(n-1) + 2*a(n-2) + a([n/2]), where a(0) = 1, a(1) = 1, a(2) = 1. %H A298415 Clark Kimberling, <a href="/A298415/b298415.txt">Table of n, a(n) for n = 0..1000</a> %t A298415 a[0] = 1; a[1] = 1; a[2] = 1; %t A298415 a[n_] := a[n] = a[n - 1] + 2 a[n - 2] + a[Floor[n/2]]; %t A298415 Table[a[n], {n, 0, 30}] (* A298415 *) %Y A298415 Cf. A298338. %K A298415 nonn,easy %O A298415 0,4 %A A298415 _Clark Kimberling_, Feb 11 2018