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 A336542 #14 Aug 27 2020 19:43:19 %S A336542 1,2,5,10,25,50,65,125,130,250,325,625,650,1105,1250,1625,2210,3125, %T A336542 3250,4225,5525,6250,8125,8450,11050,15625,16250,21125,27625,31250, %U A336542 32045,40625,42250,55250,64090,71825,78125,81250,105625,138125,143650,156250,160225,203125,211250 %N A336542 Primitive integers for the number of ways k to write as a sum of two squares. %C A336542 The number of ways to write k as a number of two squares only depends on the parity of the multiplicity of 2, the parity of the multiplicity of a prime of the form 4*m + 3 and the multiplicity of a prime of the form 4*m+1 (See A025426). Terms in this sequence have no prime factors of the form 4*m + 3. %H A336542 David A. Corneth, <a href="/A336542/b336542.txt">Table of n, a(n) for n = 1..10000</a> %e A336542 650 = 2*5*13 is in the sequence as its prime factors are 2 or of the form 4*m + 1. It's the least positive integer of the form 2*p*q where p and q are distinct and each of the form 4*m+1. %Y A336542 Cf. A025426, A054994, A274567. %K A336542 nonn %O A336542 1,2 %A A336542 _David A. Corneth_, Jul 24 2020