A062684 Number of addition triangles with apex n (version 1).

1, 2, 3, 5, 7, 10, 13, 18, 23, 29, 37, 46, 55, 68, 81, 96, 115, 135, 155, 183, 211, 241, 277, 317, 357, 407, 457, 513, 577, 645, 713, 799, 885, 977, 1079, 1191, 1305, 1438, 1571, 1717, 1875, 2048, 2221, 2423, 2625, 2840, 3077, 3333, 3589, 3876, 4163

Offset: 1

Author

Naohiro Nomoto, Feb 11 2002

Keywords

• easy
• nonn

Comments

An addition triangle has any set of positive numbers as base; other rows are formed by adding pairs of adjacent numbers.

Reversing the base counts as a different triangle.

Examples

			For n = 5:
    5       5
   2,3     3,2     5     5     5     5
  1,1,2   2,1,1   4,1   1,4   2,3   3,2   5
with seven different bases, so a(5) = 7.
		

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A028307, A066411, see A062896 for version 2.

Extensions

Extended and edited by John W. Layman, Feb 14 2002