A020838 Expansion of 1/((1-7x)(1-8x)(1-10x)).

1, 25, 419, 5885, 74811, 892605, 10199659, 113009005, 1223954171, 13030808285, 136920690699, 1424085096525, 14693717768731, 150657001125565, 1537006821834539, 15618310264486445, 158202271944562491

Offset

0,2

Links

Muniru A Asiru, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (25,-206,560).

Formula

a(n) = 25*a(n-1) - 206*a(n-2) + 560*a(n-3), n >= 3. - Vincenzo Librandi, Mar 15 2011

a(n) = 18*a(n-1) - 80*a(n-2) + 7^n, n >= 2. - Vincenzo Librandi, Mar 15 2011

a(n) = 7^(n+2)/3 + 5*10^(n+1)/3 - 4*8^(n+1). - R. J. Mathar, Mar 15 2011

Maple

[seq(coeftayl(1/((1-7*x)*(1-8*x)*(1-10*x)), x = 0, k), k=1..20)]; # Muniru A Asiru, Mar 19 2018

Mathematica

Table[SeriesCoefficient[1/((1 - 7x)(1 - 8x)(1 - 10x)), {x, 0, n}], {n, 0, 19}] (* Alonso del Arte, Mar 19 2018 *)

Prog

(PARI) x='x+O('x^99); Vec(1/((1-7*x)*(1-8*x)*(1-10*x))) \\ Altug Alkan, Mar 19 2018
(GAP) a:=[1, 25, 419];; for n in [4..20] do a[n]:=25*a[n-1]-206*a[n-2]+560*a[n-3]; od; a; # Muniru A Asiru, Mar 19 2018

Crossrefs

Sequence in context: A023952 A025991 A022628 * A025975 A025953 A020595

Adjacent sequences: A020835 A020836 A020837 * A020839 A020840 A020841

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved