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A005647 Salie numbers.
(Formerly M3066)
8
1, 1, 3, 19, 217, 3961, 105963, 3908059, 190065457, 11785687921, 907546301523, 84965187064099, 9504085749177097, 1251854782837499881, 191781185418766714683, 33810804270120276636139, 6796689405759438360407137, 1545327493049348356667631841 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

REFERENCES

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 87, Problem 32.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

T. D. Noe, Table of n, a(n) for n=0..100

FORMULA

Expand cosh x / cos x and multiply coefficients by n!/(2^(n/2)).

a(n) = 2^(-n)*Sum_{k=0..n} A000364(k)*binomial(2*n, 2*k)). - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Jul 30 2003

CROSSREFS

a(n) = A000795(n)/2^n.

Sequence in context: A058165 A074707 A135749 * A158876 A001833 A001035

Adjacent sequences:  A005644 A005645 A005646 * A005648 A005649 A005650

KEYWORD

nonn,easy,nice

AUTHOR

Simon Plouffe (simon.plouffe(AT)gmail.com), N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 17 16:00 EST 2012. Contains 206050 sequences.