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A177730
Expansion of (6*x + 1) / ((x - 1)*(2*x - 1)*(4*x - 1)*(8*x - 1)).
1
1, 21, 245, 2325, 20181, 168021, 1370965, 11075925, 89042261, 714081621, 5719635285, 45785027925, 366392038741, 2931583636821, 23454458533205, 187642826282325, 1501171242849621, 12009484474209621, 96076333921424725, 768612503886583125, 6148907361161794901
OFFSET
0,2
FORMULA
From Colin Barker, Jan 27 2018: (Start)
a(n) = ((2^(n+1)-1)^2 * (2^(n+2)-1)) / 3.
a(n) = 15*a(n-1) - 70*a(n-2) + 120*a(n-3) - 64*a(n-4) for n>3.
(End)
MAPLE
a := seq(((2^(n+1)-1)^2 * (2^(n+2)-1))/3, n = 0..200); # Muniru A Asiru, Jan 27 2018
MATHEMATICA
CoefficientList[Series[(6x+1)/((x-1)(2x-1)(4x-1)(8x-1)), {x, 0, 30}], x] (* or *) LinearRecurrence[{15, -70, 120, -64}, {1, 21, 245, 2325}, 30] (* Harvey P. Dale, Jul 16 2018 *)
PROG
(GAP) a := List([0..200], n->((2^(n+1)-1)^2*(2^(n+2)-1))/3); # Muniru A Asiru, Jan 27 2018
(PARI) Vec((6*x + 1) / ((x - 1)*(2*x - 1)*(4*x - 1)*(8*x - 1)) + O(x^30)) \\ Colin Barker, Jan 27 2018
CROSSREFS
Sequence in context: A175843 A198974 A271792 * A199300 A302992 A344919
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, May 12 2010
EXTENSIONS
Heavily edited, with the blessing of Michel Marcus and Joerg Arndt, by Colin Barker, Jan 27 2018
STATUS
approved