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A100167
Structured pentagonal icositetrahedral numbers (vertex structure 13).
2
1, 38, 171, 460, 965, 1746, 2863, 4376, 6345, 8830, 11891, 15588, 19981, 25130, 31095, 37936, 45713, 54486, 64315, 75260, 87381, 100738, 115391, 131400, 148825, 167726, 188163, 210196, 233885, 259290, 286471, 315488
OFFSET
1,2
FORMULA
a(n) = (1/6)*(60*n^3 - 72*n^2 + 18*n).
G.f.: x*(1 + 34*x + 25*x^2)/(1-x)^4. - Colin Barker, Feb 14 2012
MATHEMATICA
Table[(60n^3-72n^2+18n)/6, {n, 40}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {1, 38, 171, 460}, 40] (* Harvey P. Dale, Aug 21 2016 *)
PROG
(Magma) [(1/6)*(60*n^3-72*n^2+18*n): n in [1..40]]; // Vincenzo Librandi, Jul 26 2011
CROSSREFS
Cf. A100168 = alternate vertex; A100145 for more on structured numbers.
Sequence in context: A135176 A318625 A281208 * A100168 A137022 A160064
KEYWORD
easy,nonn
AUTHOR
James A. Record (james.record(AT)gmail.com), Nov 07 2004
STATUS
approved