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.

A168260 Triangle read by rows, A168258 * the diagonalized variant of A168259.

Original entry on oeis.org

1, 1, 1, 2, 2, 2, 2, 2, 4, 6, 3, 3, 6, 12, 14, 3, 3, 6, 18, 28, 38, 4, 4, 8, 24, 42, 76, 96, 4, 4, 8, 24, 56, 114, 192, 254, 5, 5, 10, 30, 70, 152, 288, 508, 656, 5, 5, 10, 30, 70, 190, 384, 762, 1312, 1724, 6, 6, 12, 36, 84, 228, 480, 1016
Offset: 1

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Author

Gary W. Adamson, Nov 21 2009

Keywords

Comments

Row sums = A168259: (1, 2, 6, 14, 38, 96, ...).
Sum of n-th row terms = rightmost term of next row.
Conjecture: Row sum ratios tend to phi^2 = 2.6180339... (cf. A168259).

Examples

			Triangle begins:
  1;
  1, 1;
  2, 2,  2;
  2, 2,  4,  6;
  3, 3,  6, 12,  14;
  3, 3,  6, 18,  28,  38;
  4, 4,  8, 24,  42,  76,  96;
  4, 4,  8, 24,  56, 114, 192,  254;
  5, 5, 10, 30,  70, 152, 288,  508,  656;
  5, 5, 10, 30,  70, 190, 384,  762, 1312,  1724;
  6, 6, 12, 36,  84, 228, 480, 1016, 1968,  3448,  4492;
  6, 6, 12, 36,  84, 228, 576, 1270, 2624,  5172,  8984, 11776;
  7, 7, 14, 42,  98, 266, 672, 1524, 3284,  6896, 13476, 23552,  30774;
  7, 7, 14, 42,  98, 266, 672, 1778, 3936,  8620, 17968, 35328,  61548,  80608;
  8, 8, 16, 48, 112, 304, 768, 2032, 5248, 12068, 26952, 58880, 123096, 241824;
  ...
		

Crossrefs

Formula

Let M = triangle A168258 and Q = the diagonalized variant of M's eigensequence
such that Q's rightmost diagonal = A168259 prefaced with a 1: (1, 1, 2, 6, ...).
and other terms = 0.
Triangle A168260 = M * Q as infinite lower triangular matrices.