login
A016198
Expansion of 1/((1-x)(1-2x)(1-5x)).
0
1, 8, 47, 250, 1281, 6468, 32467, 162590, 813461, 4068328, 20343687, 101722530, 508620841, 2543120588, 12715635707, 63578244070, 317891351421, 1589457019248, 7947285620527, 39736429151210, 198682147853201, 993410743460308, 4967053725690147, 24835268645227950
OFFSET
0,2
FORMULA
a(n) = (25*5^n-16*2^n+3)/12. - Bruno Berselli, Feb 09 2011
a(n) = [(5^0-2^0) + (5^1-2^1) + ... + (5^n-2^n)]/3. - r22lou(AT)cox.net, Nov 14 2005
a(0)=1, a(n)=5*a(n-1)+2^(n+1)-1. - Vincenzo Librandi, Feb 07 2011
MAPLE
a:=n->sum((5^(n-j)-2^(n-j))/3, j=0..n): seq(a(n), n=1..20); # Zerinvary Lajos, Jan 04 2007
MATHEMATICA
Join[{a=1, b=8}, Table[c=7*b-10*a+1; a=b; b=c, {n, 60}]] (* Vladimir Joseph Stephan Orlovsky, Feb 06 2011 *)
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Dec 11 1999
EXTENSIONS
More terms from Wesley Ivan Hurt, May 05 2014
STATUS
approved