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A227273
Expansion of 1/((1-x)*(1-4*x)*(1-10*x)*(1-20*x)*(1-35*x)).
1
1, 70, 3321, 135450, 5143341, 188253030, 6755426161, 239789821810, 8459827013781, 297439462109790, 10437310023978201, 365844613023404970, 12815338551339471421, 448752409725746315350, 15710645734163363925441, 549958830422813492568930, 19250283677858902044252261
OFFSET
0,2
COMMENTS
Note that the denominator has 5 tetrahedral numbers: 1, 4, 10, 20, 35.
LINKS
FORMULA
a(n) = (2736*35^(n+4) - 23715*20^(n+4) + 80104*10^(n+4) - 121125*4^(n+4) + 62000)/1081404000.
MATHEMATICA
CoefficientList[Series[1/((1 - x) (1 - 4 x) (1 - 10 x) (1 - 20 x) (1 - 35 x)), {x, 0, 50}], x] (* G. C. Greubel, Oct 02 2017 *)
PROG
(PARI) Vec(1/((1-x)*(1-4*x)*(1-10*x)*(1-20*x)*(1-35*x)) + O(x^50)) \\ Michel Marcus, May 23 2014
CROSSREFS
Column k=4 of A080249.
Sequence in context: A075923 A089274 A266739 * A298463 A275295 A306984
KEYWORD
nonn,easy
AUTHOR
Yahia Kahloune, Jul 04 2013
EXTENSIONS
Typo in a(7) fixed by Colin Barker, May 23 2014
STATUS
approved