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A119502 A025581(n)!. 3
1, 1, 1, 2, 1, 1, 6, 2, 1, 1, 24, 6, 2, 1, 1, 120, 24, 6, 2, 1, 1, 720, 120, 24, 6, 2, 1, 1, 5040, 720, 120, 24, 6, 2, 1, 1, 40320, 5040, 720, 120, 24, 6, 2, 1, 1, 362880, 40320, 5040, 720, 120, 24, 6, 2, 1, 1, 3628800, 362880, 40320, 5040, 720, 120, 24, 6, 2, 1, 1, 39916800 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,4

COMMENTS

The reciprocal of each entry in a lower triangular readout of the exponential of a matrix whose entry {j+1,j} equals one (and all other entries are zero). Note all said entries are unit fractions (all numerators are one).

Denominators of unfinished fractional coefficients for polynomials 152650/A152656 =A009998/A119052. [From Paul Curtz (bpcrtz(AT)free.fr), Dec 13 2008]

FORMULA

T(n,k) = (n-k)! a(n) = Gamma[binomial[1 + Floor[(1/2) + Sqrt[2*(1 + n)]], 2] - n]

EXAMPLE

1; 1, 1; 2, 1, 1; 6, 2, 1, 1; 24, 6, 2, 1, 1; ...

MATHEMATICA

Table[Gamma[Binomial[1 + Floor[(1/2) + Sqrt[2*(1 + n)]], 2] - n], {n, 0, 77}]

CROSSREFS

Cf. A025581.

Sequence in context: A179380 A107106 A178249 * A142156 A136707 A179972

Adjacent sequences:  A119499 A119500 A119501 * A119503 A119504 A119505

KEYWORD

easy,nonn,tabl

AUTHOR

Joseph Biberstine (jrbibers(AT)indiana.edu), May 26 2006

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Last modified February 17 13:28 EST 2012. Contains 206031 sequences.