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 A054057 #7 Jul 02 2025 16:01:59
%S A054057 41,43,47,49,53,59,61,71,73,83,91,97,113,131,139,151,169,173,197,203,
%T A054057 223,241,251,281,283,313,329,347,379,383,421,433,461,491,503,547,553,
%U A054057 593,619,641,689,691,743,763,797,841,853,911,923,971,1009,1033,1097
%N A054057 Numbers of form 41+n^2+n or 41+2*n^2.
%e A054057 41 + 18 =59 and 41 + 20 =61
%t A054057 With[{nn=60},Take[Flatten[Table[{41+n^2+n , 41+2n^2},{n,0,nn}]]//Union,nn]] (* _Harvey P. Dale_, Aug 03 2017 *)
%Y A054057 Cf. A052293, A054056.
%K A054057 nonn,easy
%O A054057 1,1
%A A054057 Stuart M. Ellerstein (ellerstein(AT)aol.com), Apr 28 2000
%E A054057 More terms from _James Sellers_, Apr 30 2000