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 A328637 #25 Dec 05 2019 19:52:04 %S A328637 1,3,6,4,11,10,18,8,17,20,29,12,42,34,32,28,59,18,78,48,53,56,101,24, %T A328637 43,82,27,76,130,54,161,75,86,116,110,36,198,154,125,67,239,96,282, %U A328637 120,81,200,329,48,116,98,176,172,382,54,165,137,233,258,441 %N A328637 Change the array in A125624 by putting a 1 at the top of the first column and pushing that column down by one place; a(n) is the sum of the terms in the modified array down to and including n, in the column that contains n. %H A328637 J. Stauduhar, <a href="/A328637/a328637_1.py.txt">Python program</a> %e A328637 The modified version of the array A125624 is: %e A328637 1, 4, 8, 16, 32, 64, 128, 256, 512, ... %e A328637 2, 6, 9, 12, 18, 24, 27, 36, 48, ... %e A328637 3, 10, 15, 20, 25, 30, 40, 45, 50, ... %e A328637 5, 14, 21, 28, 35, 42, 49, 56, 63, ... %e A328637 7, 22, 33, 44, 55, 66, 77, 88, 99, ... %e A328637 11, 26, 39, 52, 65, 78, 91, 104, 117, ... %e A328637 ... %e A328637 Then: %e A328637 a(1) = 1, %e A328637 a(2) = 1+2, %e A328637 a(3) = 1+2+3, %e A328637 a(4) = 4, %e A328637 a(5) = 1+2+3+5, %e A328637 a(6) = 4+6, %e A328637 ... %Y A328637 Cf. A125624, A328638. %K A328637 nonn,easy %O A328637 1,2 %A A328637 _J. Stauduhar_, Oct 22 2019 %E A328637 Edited by _N. J. A. Sloane_, Dec 05 2019