login
A062684
Number of addition triangles with apex n (version 1).
8
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
1,2
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 counts as a different triangle.
LINKS
EXAMPLE
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.
CROSSREFS
Cf. A028307, A066411, see A062896 for version 2.
Sequence in context: A347647 A008766 A103232 * A341912 A033485 A026811
KEYWORD
easy,nonn
AUTHOR
Naohiro Nomoto, Feb 11 2002
EXTENSIONS
Extended and edited by John W. Layman, Feb 14 2002
STATUS
approved