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 A136345 #8 Feb 16 2025 08:33:07
%S A136345 2,9,16,22,29,41,42,48,61,66,73,80,86,97,104,105,117,130,134,136,141,
%T A136345 154,161,173,177,184,192,197,198,216,226,229,233,241,246,265,266,272,
%U A136345 281,288,290,301,309,320,321,342,345,349,352,358,362,376,381,401,406,409
%N A136345 Sums of exactly two positive octagonal numbers A000567.
%C A136345 For octagonal numbers within this sequence, see: A136346. This is to octagonal numbers A000567 as A051533 is to triangular numbers A000217 and as A000404 is to squares A000290 and as A117104 is to heptagonal numbers A000566.
%H A136345 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/OctagonalNumber.html">Octagonal Number</a>.
%F A136345 {A000567(i) + A000567(j), i, j > 0}. {i*(3*i-2) + j(3*j-2), i, j > 0}.
%Y A136345 Cf. A000567, A136117, A136346.
%K A136345 easy,nonn
%O A136345 1,1
%A A136345 _Jonathan Vos Post_, Dec 25 2007
%E A136345 Missing term (80) from _Giovanni Resta_, Jun 19 2016