cp's OEIS Frontend

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.

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.

Original entry on oeis.org

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, 82, 100, 26, 21, 4, 1, 1, 65, 244, 354, 126, 91, 16, 6, 1, 1, 129, 730, 1300, 626, 441, 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
Offset: 1

Views

Author

Ilya Gutkovskiy, May 29 2019

Keywords

Examples

			Square array begins:
  1,   1,   1,    1,    1,     1,  ...
  1,   1,   1,    1,    1,     1,  ...
  2,   3,   5,    9,   17,    33,  ...
  2,   4,  10,   28,   82,   244,  ...
  4,  10,  30,  100,  354,  1300,  ...
  2,   6,  26,  126,  626,  3126,  ...
		

Crossrefs

Columns k=0..4 give A000010, A023896, A053818, A053819, A053820.
Cf. A103438.

Programs

  • Mathematica
    Table[Function[k, Sum[If[GCD[n, j] == 1, j^k, 0], {j, 1, n}]][i - n], {i, 0, 12}, {n, 1, i}] // Flatten