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A100165 Structured rhombic triacontahedral numbers (vertex structure 7). 5
1, 32, 147, 400, 845, 1536, 2527, 3872, 5625, 7840, 10571, 13872, 17797, 22400, 27735, 33856, 40817, 48672, 57475, 67280, 78141, 90112, 103247, 117600, 133225, 150176, 168507, 188272, 209525, 232320, 256711, 282752 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Also structured pentakis dodecahedral numbers (vertex structure 7) (cf. A100173 = alternate vertex).

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..5000

FORMULA

a(n) = (1/6)*(54*n^3 - 72*n^2 + 24*n) = n*(3*n-2)^2.

From Jaume Oliver Lafont, Sep 08 2009: (Start)

a(n) = (3*(n-1) + 1)^2*(3*(n-1) + 3)/3.

G.f.: x*(1 + 28*x + 25*x^2)/(1-x)^4. (End)

PROG

(MAGMA) [(1/6)*(54*n^3-72*n^2+24*n): n in [1..40]]; // Vincenzo Librandi, Jul 26 2011

CROSSREFS

Cf. A100164 = alternate vertex; A100145 for more on structured numbers.

Cf. A260260 (comment). [Bruno Berselli, Jul 22 2015]

Sequence in context: A297342 A228758 A097199 * A100173 A234874 A220975

Adjacent sequences:  A100162 A100163 A100164 * A100166 A100167 A100168

KEYWORD

nonn,easy

AUTHOR

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

STATUS

approved

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Last modified October 16 05:56 EDT 2019. Contains 328046 sequences. (Running on oeis4.)