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A051289 Triangular array T read by rows: T(n,k)=P(2n+1,n,2k+1), where P(n,k,c)=number of vectors (x(1),x(2,),...,x(n)) of k 1's and n-k 0's such that x(i)=x(n+1-i) for exactly c values of i. 0
1, 2, 1, 4, 4, 2, 8, 12, 12, 3, 16, 32, 48, 24, 6, 32, 80, 160, 120, 60, 10, 64, 192, 480, 480, 360, 120, 20, 128, 448, 1344, 1680, 1680, 840, 280, 35, 256, 1024, 3584, 5376, 6720, 4480, 2240, 560, 70, 512, 2304, 9216, 16128, 24192 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

P(n,k,n) counts palindromes.

LINKS

Table of n, a(n) for n=0..49.

FORMULA

E.g.f.: exp(2*y)*(BesselI(0, 2*x*y)+BesselI(1, 2*x*y)). - Vladeta Jovovic, Dec 15 2004

EXAMPLE

Rows: (1); (2,1}; {4,4,2}; ...

CROSSREFS

Cf. A001700 (=row sums).

Sequence in context: A247248 A192017 A180566 * A090802 A129159 A095830

Adjacent sequences:  A051286 A051287 A051288 * A051290 A051291 A051292

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified April 25 08:35 EDT 2018. Contains 303055 sequences. (Running on oeis4.)