A062896 Number of addition triangles with apex n (version 2).

1, 2, 2, 4, 4, 7, 7, 12, 12, 18, 19, 27, 28, 39, 41, 54, 58, 74, 78, 99, 106, 129, 139, 168, 179, 214, 229, 268, 289, 335, 357, 414, 443, 504, 540, 612, 653, 737, 786, 878, 938, 1045, 1111, 1234, 1313, 1444, 1539, 1692, 1795, 1965, 2082, 2273, 2414

Offset

1,2

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 does not count as a different triangle.

Links

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

Example

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

Crossrefs

See A062684 for version 1 (counts reversals).

Equivalent sequences with restrictions on rows: A337765 (weakly increasing), A337766 (strongly increasing).

Equivalent sequence where n is the sum of all numbers in the triangle: A337787.

Cf. A028307, A066411.

Sequence in context: A266776 A371514 A363214 * A025065 A306664 A365826

Adjacent sequences: A062893 A062894 A062895 * A062897 A062898 A062899

Keyword

easy,nonn

Author

Naohiro Nomoto, Feb 11 2002

Extensions

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

Status

approved