A291987 Expansion of 1/((1-x)*(1-2*x^2)*(1-3*x^3)*(1-4*x^4)).

1, 1, 3, 6, 14, 20, 45, 69, 135, 210, 378, 576, 1057, 1561, 2667, 4110, 6902, 10220, 17109, 25485, 41583, 62250, 99666, 147960, 238633, 350881, 553107, 825126, 1292942, 1899620, 2977821, 4381269, 6791127, 10025730, 15415722, 22645296, 34970545, 51140521

Offset: 0

Author

Seiichi Manyama, Sep 07 2017

Keywords

• nonn
• easy

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..6271
• Index entries for linear recurrences with constant coefficients, signature (1,2,1,1,-10,-2,-4,12,24,-24).

Crossrefs

Cf. A291960, A291986, A291988.

Programs

GAP

a:=[1,1,3,6,14,20,45,69,135,210];;
for n in [11..10^2] do a[n]:=a[n-1]+2*a[n-2]+a[n-3]+a[n-4]-10*a[n-5]-2*a[n-6]-4*a[n-7]+12*a[n-8]+24*a[n-9]-24*a[n-10]; od; a; # Muniru A Asiru, Sep 07 2017

PARI

Vec(1/((1-x)*(1-2*x^2)*(1-3*x^3)*(1-4*x^4)) + O(x^100))

Formula

a(n) = a(n-1) + 2*a(n-2) + a(n-3) + a(n-4) - 10*a(n-5) - 2*a(n-6) - 4*a(n-7) + 12*a(n-8) + 24*a(n-9) - 24*a(n-10) for n >= 11. - Muniru A Asiru, Sep 07 2017