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A048854 Triangle of coefficients of certain Sheffer-polynomials. +0
24
1, 2, 1, 12, 12, 1, 120, 180, 30, 1, 1680, 3360, 840, 56, 1, 30240, 75600, 25200, 2520, 90, 1, 665280, 1995840, 831600, 110880, 5940, 132, 1, 17297280, 60540480, 30270240, 5045040, 360360, 12012, 182, 1, 518918400, 2075673600, 1210809600 (list; table; graph; listen)
OFFSET

0,2

COMMENT

s(n,x) := sum(a(n,m)*x^m,m=0..n) are monic polynomials satisfying s(n,x+y) = sum(binomial(n,k)*s(k,x)*p(n-k,y),k=0..n), with polynomials p(n,x)=sum(A048786(n,m)*x^m, m=1..n) (row polynomials of triangle A048786) and p(0,x)=1.

In the umbral calculus (see reference) the s(n,x) are called Sheffer polynomials for(1/sqrt(1+4*t),t/(1+4*t)).

REFERENCES

S. Roman, The Umbral Calculus, Academic Press, New York, 1984.

FORMULA

a(n, m) = (n!/m!)*A046521(n, m) = (n!/m!)* binomial(2*n, n)*binomial(n, m)/binomial(2*m, m), n >= m >= 0, a(n, m) := 0, n<m.

Sum_{n>=0, k>=0} a(n, k)*x^n*y^k/(2*n)! = exp(x)*cosh(sqrt(x*y)). - Vladeta Jovovic (vladeta(AT)eunet.rs), Feb 21 2003

CROSSREFS

Related to triangle A046521. Cf. A048786. a(n, 0) = A001813.

Sequence in context: A130559 A135256 A090586 this_sequence A151508 A164826 A055392

Adjacent sequences: A048851 A048852 A048853 this_sequence A048855 A048856 A048857

KEYWORD

easy,nonn,tabl

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)

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Last modified November 22 14:50 EST 2009. Contains 167310 sequences.


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