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A100175 Structured triakis tetrahedral numbers (vertex structure 4). 6
1, 8, 30, 76, 155, 276, 448, 680, 981, 1360, 1826, 2388, 3055, 3836, 4740, 5776, 6953, 8280, 9766, 11420, 13251, 15268, 17480, 19896, 22525, 25376, 28458, 31780, 35351, 39180, 43276, 47648, 52305, 57256, 62510, 68076, 73963, 80180, 86736, 93640, 100901, 108528 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Equals binomial transform of [1, 7, 15, 9, 0, 0, 0,...] where (1, 7, 15, 9) = row 3 of triangle A038763. - Gary W. Adamson, Jul 19 2008

Equals convolution square of 1, 4, 7, 10, 13, 16, 19,..., A016777. - Gary W. Adamson, Jul 28 2009

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

FORMULA

a(n) = (3*n^3-3*n^2+2*n)/2.

G.f.: x*(2*x+1)^2 / ( (x-1)^4 ).

PROG

(MAGMA) [(3*n^3-3*n^2+2*n)/2: n in [1..50] ]; // Vincenzo Librandi, Aug 02 2011

CROSSREFS

Cf. A000578 = alternate vertex; A100145 for more on structured numbers.

Cf. A038763.

Sequence in context: A131769 A055832 A195753 * A063489 A299284 A002417

Adjacent sequences:  A100172 A100173 A100174 * A100176 A100177 A100178

KEYWORD

easy,nonn

AUTHOR

James A. Record (james.record(AT)gmail.com), Nov 07 2004

STATUS

approved

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Last modified December 10 23:29 EST 2019. Contains 329910 sequences. (Running on oeis4.)