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 A180425 #30 Feb 16 2025 08:33:13
%S A180425 2,42,505,5586,59308,616995,6347878,64875490,660104281,6695709182,
%T A180425 67762820595,684596704482,6907026402474,69611115440126,
%U A180425 700946070114283,7053023642205904
%N A180425 Number of positive integers below 10^n requiring 3 positive squares in their representation as sum of squares.
%H A180425 Eric W. Weisstein, <a href="https://mathworld.wolfram.com/LagrangesFour-SquareTheorem.html">MathWorld -- Lagrange's Four-Square Theorem.</a>
%H A180425 Eric W. Weisstein, <a href="https://mathworld.wolfram.com/SumofSquaresFunction.html">MathWorld -- Sum of Squares Function.</a>
%F A180425 a(n) = #{k: A000419(k) < 10^n}.
%F A180425 A049416(n) + A180416(n) + a(n) + A167615(n) = A002283(n).
%Y A180425 Cf. A000419, A049416, A180416, A167615, A002283.
%K A180425 nonn,more
%O A180425 1,1
%A A180425 _Martin Renner_, Jan 19 2011
%E A180425 a(6)=616995 by _Lars Blomberg_, May 03 2011
%E A180425 a(7)-a(10) from _Donovan Johnson_, Jul 01 2011
%E A180425 a(10) corrected and a(11)-a(16) from _Hiroaki Yamanouchi_, Jul 13 2014