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A211386 Expansion of 1/((1-2*x)^5*(1-x)). 3
1, 11, 71, 351, 1471, 5503, 18943, 61183, 187903, 553983, 1579007, 4374527, 11829247, 31326207, 81461247, 208470015, 525991935, 1310457855, 3228041215, 7870611455, 19012780031, 45541752831, 108246597631, 255466668031, 598980165631, 1395931480063, 3235049897983 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Occurs in the enumerations of inflations of code words babxxxdc [Albert et al. Sec 5.5.1]

LINKS

Table of n, a(n) for n=0..26.

M. H. Albert, M. D. Atkinson, R. Brignall, The enumeration of three pattern classes using monotone grid classes, El. J. Combinat. 19 (3) (2012) P20.

Harry Crane, Left-right arrangements, set partitions, and pattern avoidance, Australasian Journal of Combinatorics, 61(1) (2015), 57-72.

Index entries for linear recurrences with constant coefficients, signature (11,-50,120,-160,112,-32).

FORMULA

a(n) = 2^n*(24+18*n+23*n^2+6*n^3+n^4)/12-1.

a(0)=1, a(1)=11, a(2)=71, a(3)=351, a(4)=1471, a(5)=5503, a(n)=11*a(n-1)- 50*a(n-2)+ 120*a(n-3)-160*a(n-4)+112*a(n-5)-32*a(n-6). - Harvey P. Dale, Mar 02 2015

MATHEMATICA

CoefficientList[Series[1/((1-2x)^5(1-x)), {x, 0, 30}], x] (* or *) LinearRecurrence[ {11, -50, 120, -160, 112, -32}, {1, 11, 71, 351, 1471, 5503}, 30] (* Harvey P. Dale, Mar 02 2015 *)

PROG

(PARI) Vec(1/((1-2*x)^5*(1-x))+ O(x^30)) \\ Michel Marcus, Feb 12 2015

CROSSREFS

Cf. A003472 (first differences).

Sequence in context: A174822 A201790 A268985 * A049350 A164559 A319535

Adjacent sequences:  A211383 A211384 A211385 * A211387 A211388 A211389

KEYWORD

nonn,easy

AUTHOR

R. J. Mathar, Feb 07 2013

STATUS

approved

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Last modified February 26 00:08 EST 2020. Contains 332270 sequences. (Running on oeis4.)