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 A185243 #14 Dec 28 2024 21:34:37
%S A185243 36,276,1081,1770,5886,5671,12246,16653,60031,60726,147153,293761,
%T A185243 264628,257403,574056,665281,477753,1345620,1512930,1450956,2039190,
%U A185243 1695561,1682695,3454506,3560446,3932610,2595781,3589860,3969153,4258821,8427565,9003646,12110581
%N A185243 a(n) = A185128(n) + A185129(n).
%C A185243 See A185128 for further information.
%D A185243 Albert H. Beiler, Recreations in the theory of numbers, New York, Dover, (2nd ed.) 1966, p. 197, no. 8.
%H A185243 N. J. A. Sloane, <a href="/A185128/a185128.jpg">Annotated scan of Beiler's Table 81</a>, based on page 197 of Beiler's "Recreations in the Theory of Numbers: The Queen of Mathematics Entertains", New York, Dover, First ed., 1964.
%o A185243 (PARI) lista(nn) = {v = vector(nn, n, n*(n+1)/2); for (n=2, nn, for (k=1, n-1, if (ispolygonal(v[n]+v[k], 3) && ispolygonal(v[n]-v[k], 3), print1(v[n]+v[k], ", "));););} \\ _Michel Marcus_, Jan 08 2015
%Y A185243 Cf. A000217, A185128, A185129, A185223, A185233, A185253, A185257, A185258.
%K A185243 nonn
%O A185243 1,1
%A A185243 _Martin Renner_, Jan 20 2012
%E A185243 Edited by _N. J. A. Sloane_, Dec 28 2024 (replaced definition with simpler and more explicit formula from _Michel Marcus_, Jan 08 2015)