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.

A360020 Irregular triangle T(n, k), n > 0, k = 1..A056137(A009023(n)), read by rows: T(n, k) is the square root of A009023(n)^2 + A359805(n, k)^2.

Original entry on oeis.org

5, 10, 13, 15, 17, 20, 25, 29, 25, 26, 30, 35, 34, 40, 37, 39, 45, 41, 50, 58, 55, 51, 53, 50, 52, 60, 65, 73, 65, 70, 61, 65, 68, 75, 65, 87, 80, 85, 74, 75, 78, 90, 97, 85, 95, 85, 82, 89, 100, 85, 91, 105, 116, 110, 102, 106, 109, 115, 100, 104, 120, 101
Offset: 1

Views

Author

Rémy Sigrist, Mar 08 2023

Keywords

Examples

			Triangle T(n, k) begins:
  n   A009023(n)  n-th row
  --  ----------  ----------
   1           4  5
   2           8  10
   3          12  13, 15
   4          15  17
   5          16  20
   6          20  25
   7          21  29
   8          24  25, 26, 30
   9          28  35
  10          30  34
  11          32  40
  12          35  37
  13          36  39, 45
  14          40  41, 50
		

Crossrefs

Programs

  • PARI
    { for (n=1, 99, for (m=1, n-1, if (issquare(n^2 + m^2, &h), print1 (h", ")))) }

Formula

T(n, k) = A000196(A009023(n)^2 + A359805(n, k)^2).