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A171999 Triangle of trinomial coefficients. 0
1, 1, 2, 1, 3, 6, 1, 4, 6, 12, 1, 5, 10, 20, 30, 1, 6, 15, 20, 30, 60, 90, 1, 7, 21, 35, 42, 105, 140, 210, 1, 8, 28, 56, 70, 168, 280, 420, 560, 1, 9, 36, 72, 84, 126, 252, 504, 630, 756, 1260, 1680, 1, 10, 45, 90, 120, 210, 252, 360, 840, 1260, 2520, 3150, 4200, 1, 11, 55 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Number of numbers in row n is given by A086753.

Row sums: A092255.

See A046816, Pascal's pyramid of trinomial coefficients.

LINKS

Table of n, a(n) for n=1..67.

EXAMPLE

First six rows:

1

1...2

1...3...6

1...4...6....12

1...5...10...20...30

1...6...15...20...30...60...90

CROSSREFS

Cf. A036038, A046816, A092255.

Sequence in context: A322044 A010251 A051537 * A036038 A210237 A078760

Adjacent sequences:  A171996 A171997 A171998 * A172000 A172001 A172002

KEYWORD

nonn,tabf

AUTHOR

Clark Kimberling, Jan 21 2010

STATUS

approved

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Last modified August 3 05:55 EDT 2020. Contains 336197 sequences. (Running on oeis4.)