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 A342903 #14 Feb 21 2025 23:50:44 %S A342903 50,27,28,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39, %T A342903 40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62, %U A342903 63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86 %N A342903 a(n) is the smallest number that is the sum of n positive squares in two ways. %C A342903 This is r(n,2,2) in Alter's notation. %H A342903 R. Alter, <a href="https://doi.org/10.1007/BFb0096461">Computations and generalizations on a remark of Ramanujan</a>, pp. 182-196 of "Analytic Number Theory (Philadelphia, 1980)", ed. M. I. Knopp, Lect. Notes Math., Vol. 899, 1981. See Eq. (15), page 188. %H A342903 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1). %F A342903 a(n) = n+15 for n >= 5. %e A342903 a(2) = 50 = 1+49 = 25+25. %e A342903 a(3) = 27 = 1+1+25 = 9+9+9. %e A342903 a(5) = 20 = 1+1+1+1+16 = 4+4+4+4+4. %Y A342903 Cf. A230563, A342902. %K A342903 nonn,easy %O A342903 2,1 %A A342903 _N. J. A. Sloane_, Apr 03 2021