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A221862 Expansion of (1-3*x+x^2)*(1-x)/(1-9*x+28*x^2-35*x^3+15*x^4-x^5). 1
1, 5, 21, 83, 319, 1208, 4535, 16932, 62986, 233702, 865513, 3201026, 11826582, 43660921, 161090910, 594092895, 2190225106, 8072519511, 29746921227, 109599320930, 403758993204, 1487294628182, 5478244777582, 20177275278559, 74313150143975, 273687550281967 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

A diagonal of the square array A223968.

LINKS

Table of n, a(n) for n=0..25.

FORMULA

a(n) = A223968(n,n+3).

G.f.: (1-3*x+x^2)*(1-x)/(1-9*x+28*x^2-35*x^3+15*x^4-x^5).

a(n) = 9*a(n-1) - 28*a(n-2) + 35*a(n-3) - 15*a(n-4) + a(n-5) with a(0) = 1, a(1) = 5, a(2) = 21, a(3) = 83, a(4) = 319.

CROSSREFS

Cf. A223968

Sequence in context: A303647 A147504 A217783 * A216271 A026017 A132310

Adjacent sequences:  A221859 A221860 A221861 * A221863 A221864 A221865

KEYWORD

nonn,easy

AUTHOR

Philippe Deléham, Apr 10 2013

STATUS

approved

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Last modified August 9 07:37 EDT 2022. Contains 356019 sequences. (Running on oeis4.)