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 A347806 #10 Sep 14 2021 20:48:34 %S A347806 1,1,1,4,5,6,10,14,22,30,41,62,88,123,173,248,354,500,710,1006,1427, %T A347806 2024,2867,4066,5767,8176,11591,16436,23301,33032,46832,66396,94137, %U A347806 133461,189209,268252,380315,539190,764431,1083764,1536498,2178364,3088363,4378502,6207581 %N A347806 Expansion of (theta_3(x) - 1)^3 / (4 * (3 - theta_3(x))). %C A347806 Number of compositions (ordered partitions) of n into 3 or more squares. %H A347806 <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a> %F A347806 a(n) = Sum_{k=3..n} A337165(n,k). - _Alois P. Heinz_, Sep 14 2021 %p A347806 b:= proc(n, t) option remember; `if`(n=0, `if`(t=0, 1, 0), add(( %p A347806 s->`if`(s>n, 0, b(n-s, max(0, t-1))))(j^2), j=1..isqrt(n))) %p A347806 end: %p A347806 a:= n-> b(n, 3): %p A347806 seq(a(n), n=3..47); # _Alois P. Heinz_, Sep 14 2021 %t A347806 nmax = 47; CoefficientList[Series[(EllipticTheta[3, 0, x] - 1)^3/(4 (3 - EllipticTheta[3, 0, x])), {x, 0, nmax}], x] // Drop[#, 3] & %Y A347806 Cf. A000290, A006456, A337165, A347805, A347807, A347808, A347809. %K A347806 nonn %O A347806 3,4 %A A347806 _Ilya Gutkovskiy_, Sep 14 2021