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A193049 Coefficient of x in the reduction by x^2->x+1 of the polynomial p(n,x) defined at Comments. 1
0, 1, 1, 2, 4, 12, 37, 105, 268, 625, 1355, 2772, 5414, 10188, 18605, 33161, 57954, 99683, 169265, 284452, 474066, 784852, 1292567, 2119923, 3465620, 5651323, 9197673, 14947276, 24263704, 39353486, 63787101, 103341963, 167366400, 270986619 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

The titular polynomials are defined recursively:  p(n,x)=x*p(n-1,x)+n(4-5*n^2+n^4)/120, with p(0,x)=1.  For an introduction to reductions of polynomials by substitutions such as x^2->x+1, see A192232 and A192744.

LINKS

Table of n, a(n) for n=0..33.

FORMULA

a(n)=7*a(n-1)-20*a(n-2)+29*a(n-3)-20*a(n-4)+*a(n-5)+8*a(n-6)-5*a(n-7)+a(n-8).

MATHEMATICA

(See A193048.)

CROSSREFS

Cf. A192232, A192744, A192951, A193048.

Sequence in context: A010551 A111942 A003701 * A114500 A148212 A149844

Adjacent sequences:  A193046 A193047 A193048 * A193050 A193051 A193052

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jul 15 2011

STATUS

approved

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Last modified May 22 21:43 EDT 2013. Contains 225583 sequences.