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.

A302248 Irregular triangle read by rows in which the odd-indexed terms of the n-th row together with the even-indexed terms of the same row but listed in reverse order give the n-th row of triangle A299778.

Original entry on oeis.org

1, 3, 2, 2, 7, 0, 3, 3, 12, 0, 0, 4, 4, 0, 15, 0, 0, 5, 5, 3, 9, 0, 0, 9, 6, 6, 0, 0, 28, 0, 0, 0, 7, 7, 0, 0, 12, 0, 0, 12, 8, 8, 8, 0, 0, 31, 0, 0, 0, 0, 9, 9, 0, 0, 0, 39, 0, 0, 0, 0, 10, 10, 0, 0, 0, 42, 0, 0, 0, 0, 11, 11, 5, 0, 0, 5, 18, 0, 0, 18, 0, 0, 12, 12, 0, 0, 0, 0, 60, 0, 0, 0, 0, 0, 13, 13, 0, 0, 5, 0
Offset: 1

Views

Author

Omar E. Pol, Apr 10 2018

Keywords

Examples

			Triangle begins (rows 1..28):
   1;
   3;
   2,  2;
   7,  0;
   3,  3;
  12,  0,  0;
   4,  4,  0;
  15,  0,  0;
   5,  5,  3;
   9,  0,  0,  9;
   6,  6,  0,  0;
  28,  0,  0,  0;
   7,  7,  0,  0;
  12,  0,  0, 12;
   8,  8,  8,  0,  0;
  31,  0,  0,  0,  0;
   9,  9,  0,  0,  0;
  39,  0,  0,  0,  0;
  10, 10,  0,  0,  0;
  42,  0,  0,  0,  0;
  11, 11,  5,  0,  0,  5;
  18,  0,  0, 18,  0,  0;
  12, 12,  0,  0,  0,  0;
  60,  0,  0,  0,  0,  0;
  13, 13,  0,  0,  5,  0;
  21,  0,  0, 21,  0,  0;
  14, 14,  6,  0,  0,  6;
  56,  0,  0,  0,  0,  0,  0;
...
For n = 21 the 21st row of A299778 is [11, 5, 0, 5, 0, 11], so the 21st row of this triangle is [11, 11, 5, 0, 0, 5].
		

Crossrefs

Row sums give A000203.
Row n has length A003056(n).
Column k starts in row A000217(k).
The number of nonzero terms in row n is A237271(n).
Column 1 is A241838.
The triangle with n rows contain A237590(n) nonzero terms.
Cf. A280850 (analog for subparts).