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 A308477 #10 May 30 2019 11:52:03 %S A308477 1,1,1,1,1,2,1,1,3,2,1,1,5,4,4,1,1,9,10,10,2,1,1,17,28,30,6,6,1,1,33, %T A308477 82,100,26,21,4,1,1,65,244,354,126,91,16,6,1,1,129,730,1300,626,441, %U A308477 84,27,4,1,1,257,2188,4890,3126,2275,496,159,20,10,1,1,513,6562,18700,15626,12201,3108,1053,140,55,4 %N A308477 Square array A(n,k), n >= 1, k >= 0, read by antidiagonals: A(n,k) = Sum_{j=1..n, gcd(n,j) = 1} j^k. %H A308477 Seiichi Manyama, <a href="/A308477/b308477.txt">Antidiagonals n = 1..140, flattened</a> %e A308477 Square array begins: %e A308477 1, 1, 1, 1, 1, 1, ... %e A308477 1, 1, 1, 1, 1, 1, ... %e A308477 2, 3, 5, 9, 17, 33, ... %e A308477 2, 4, 10, 28, 82, 244, ... %e A308477 4, 10, 30, 100, 354, 1300, ... %e A308477 2, 6, 26, 126, 626, 3126, ... %t A308477 Table[Function[k, Sum[If[GCD[n, j] == 1, j^k, 0], {j, 1, n}]][i - n], {i, 0, 12}, {n, 1, i}] // Flatten %Y A308477 Columns k=0..4 give A000010, A023896, A053818, A053819, A053820. %Y A308477 Cf. A103438. %K A308477 nonn,tabl %O A308477 1,6 %A A308477 _Ilya Gutkovskiy_, May 29 2019