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 A342611 #5 Mar 17 2021 07:58:03
%S A342611 0,1,7,8,49,15,56,57,343,64,105,71,392,113,399,400,2401,407,448,169,
%T A342611 735,176,497,463,2744,505,791,512,2793,799,2800,2801,16807,2808,2849,
%U A342611 855,3136,617,1183,904,5145,911,1232,673,3479,960,3241,3207,19208,3249,3535,1296,5537
%N A342611 a(0) = 0, a(1) = 1; a(2*n) = 7*a(n), a(2*n+1) = a(n) + a(n+1).
%F A342611 G.f.: x * Product_{k>=0} (1 + 7*x^(2^k) + x^(2^(k+1))).
%t A342611 a[0] = 0; a[1] = 1; a[n_] := If[EvenQ[n], 7 a[n/2], a[(n - 1)/2] + a[(n + 1)/2]]; Table[a[n], {n, 0, 52}]
%t A342611 nmax = 52; CoefficientList[Series[x Product[(1 + 7 x^(2^k) + x^(2^(k + 1))), {k, 0, Floor[Log[2, nmax]] + 1}], {x, 0, nmax}], x]
%Y A342611 Cf. A002487, A178569, A178590, A237711, A244643, A342610, A342614, A342615.
%K A342611 nonn
%O A342611 0,3
%A A342611 _Ilya Gutkovskiy_, Mar 16 2021