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, 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

Offset: 0

Author

Philippe Deléham, Apr 10 2013

Keywords

• nonn
• easy

Comments

A diagonal of the square array A223968.

Links

• Index entries for linear recurrences with constant coefficients, signature (9,-28,35,-15,1).

Crossrefs

Cf. A223968

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.