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 A085265 #21 Feb 16 2025 08:32:50 %S A085265 2,3,4,5,6,7,8,9,10,11,12,14,15,16,17,18,19,20,21,22,23,24,25,26,27, %T A085265 28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50, %U A085265 51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71 %N A085265 Numbers that can be written as sum of a positive squarefree number and a positive square. %C A085265 Subsequence of A011760; A085263(a(n)) > 0. %C A085265 Conjecture: a(n) = n + 2 for n > 11. That is, only 1 and 13 are missing. - _Charles R Greathouse IV_, Aug 21 2011 %C A085265 Estermann proves that only finitely many positive integers are missing from this sequence. (Probably only 1 and 13.) - _Charles R Greathouse IV_, Jul 01 2016 %H A085265 Theodor Estermann, <a href="https://eudml.org/doc/159528">Einige Sätze über quadratfreie Zahlen</a>, Mathematische Annalen 105:1 (1931), pp. 653-662. %H A085265 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SquareNumber.html">Square Number</a> %H A085265 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Squarefree.html">Squarefree</a> %o A085265 (PARI) is(n)=forstep(k=sqrtint(n-1), 1, -1, if(issquarefree(n-k^2), return(1))); 0 \\ _Charles R Greathouse IV_, Mar 12 2012 %K A085265 nonn,easy %O A085265 1,1 %A A085265 _Reinhard Zumkeller_, Jun 23 2003