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A062684 Number of addition triangles with apex n (version 1). 2
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 (list; graph; refs; listen; history; text; internal format)
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

Table of n, a(n) for n=1..51.

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: A115001 A008766 A103232 * A033485 A026811 A001401

Adjacent sequences:  A062681 A062682 A062683 * A062685 A062686 A062687

KEYWORD

easy,nonn

AUTHOR

Naohiro Nomoto, Feb 11 2002

EXTENSIONS

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

STATUS

approved

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Last modified October 19 09:28 EDT 2018. Contains 316339 sequences. (Running on oeis4.)