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A153197 Binomial transform of Bessel numbers A006789. 5
1, 2, 5, 15, 51, 189, 748, 3128, 13731, 62969, 300552, 1488704, 7634723, 40464741, 221311617, 1247444859, 7238458309, 43196661875, 264878725516, 1667564565616, 10770316016557, 71314258947903, 483765644021787, 3359905164274725 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Prefaced with a 1: (1, 1, 2, 5, 15, 51,...), convolved with A006789 =

A006789; identical to reversing k terms of one sequence then taking the dot product of

k terms of the other: e.g. A006789(6) = 143 = (51, 15, 5, 2, 1, 1) dot (1, 1, 2, 5, 14, 43)

= (51 + 15 + 10 + 10 + 14 + 43). Equals row sums of triangle A153199.

A153197 can be generated from the Hankel transform [1,1,1,...] by taking

successive iterates of the operations: (binomial transform of [1,1,1,...]

followed by INVERT transform of the result, then binomial transform of the

result, (repeat cycle)...; until the operations converge upon a two sequence

fixed limit cycle of A006789 and A153197. Or, the infinite set of operations Q may begin: INVERT transform of [1,1,1,..] followed by binomial transform of

the result, INVERT transform of the result, etc; until the operations again

converge upon A006789 and A153197. The two sequences A006789 and A153197 have the mutual relationships that

binomial transform of A006789 = A153197; while the INVERT transform of A153197 prefaced with a 1 = A006789.

Product of the two sequences (A153197 prefaced with a 1) and A006789

= A006789 with offset 1. Or, (1,1,2,5,15,51,...) * (1,1,2,5,14,43,...) = (1,2,5,14,43,...).

Conjecture: Given any sequence with Hankel transform of [1,1,1,...],

performing alternate operations: binomial transform followed by INVERT

transform, then binomial transform of the last result (repeat); or INVERT

transform starting first, will converge upon A006789 and A153197 as a two sequence limit cycle. The conjecture can be extended to any Hankel transform

(and their accompanying sequence set): analogous operations will converge

upon a Bessel-type sequence and its binomial transform.

REFERENCES

Aoife Hennessy, A Study of Riordan Arrays with Applications to Continued Fractions, Orthogonal Polynomials and Lattice Paths, Ph. D. Thesis, Waterford Institute of Technology, Oct. 2011; http://repository.wit.ie/1693/1/AoifeThesis.pdf

FORMULA

INVERTi transform of A006789, Bessel numbers with offset 1: (1, 2, 5, 14, 43, 143,...).

If the sequence is prefixed with an initial zero, the g.f. A(x) satisfies A(x) = x / (1 - 2*x - x * A( x / (1 - x))). - Michael Somos Mar 06 2011

EXAMPLE

a(4) = 15 = (1, 3, 3, 1) dot (1, 1, 2, 5) = (1 + 3 + 6 + 5).

x + 2*x^2 + 5*x^3 + 15*x^4 + 51*x^5 + 189*x^6 + 748*x^7 + 3128*x^8 + ...

PROG

(PARI) {a(n) = local( A = O(x) ); if( n<0, 0, for( k=1, ceil(n/2), A = x / (1 - 2*x - x * subst( A, x, x / (1 - x)))); polcoeff( A, n))}; /* Michael

Somos Mar 06 2011 */

CROSSREFS

Cf. A153198, A153199, A006789.

Sequence in context: A073525 A007317 A181768 * A108307 A193296 A117426

Adjacent sequences:  A153194 A153195 A153196 * A153198 A153199 A153200

KEYWORD

nonn,changed

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Dec 20 2008

EXTENSIONS

Edited by N. J. A. Sloane, Mar 06 2011

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Last modified February 15 16:39 EST 2012. Contains 205823 sequences.