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 A282971 #7 Mar 15 2017 20:27:03
%S A282971 1,0,1,0,1,1,1,2,1,3,2,4,4,6,7,9,11,15,18,24,29,37,48,58,78,92,124,
%T A282971 149,195,243,308,393,490,629,786,1004,1263,1603,2024,2564,3239,4106,
%U A282971 5184,6571,8301,10508,13298,16807,21296,26895,34082,43060,54528,68952,87245,110392,139622,176696,223484,282798,357731
%N A282971 Number of compositions (ordered partitions) of n into primes of form x^2 + y^2 (A002313).
%C A282971 Number of compositions (ordered partitions) of n into primes congruent to 1 or 2 mod 4.
%C A282971 Conjecture: every number > 16 is the sum of at most 4 primes of form x^2 + y^2.
%H A282971 <a href="/index/Com#comp">Index entries for sequences related to compositions</a>
%F A282971 G.f.: 1/(1 - Sum_{k>=1} x^A002313(k)).
%e A282971 a(12) = 4 because we have [5, 5, 2], [5, 2, 5], [2, 2, 5] and [2, 2, 2, 2, 2, 2].
%t A282971 nmax = 60; CoefficientList[Series[1/(1 - Sum[Boole[SquaresR[2, k] != 0 && PrimeQ[k]] x^k, {k, 1, nmax}]), {x, 0, nmax}], x]
%o A282971 (PARI) Vec(1/(1 - sum(k=1, 60, (isprime(k) && k%4<3)*x^k)) + O(x^61)) \\ _Indranil Ghosh_, Mar 15 2017
%Y A282971 Cf. A002124, A002313, A023360, A077608, A280917, A282906, A282970.
%K A282971 nonn
%O A282971 0,8
%A A282971 _Ilya Gutkovskiy_, Feb 25 2017