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A005406 Number of protruded partitions of n with largest part at most 5.
(Formerly M2569)
+0
1
1, 3, 6, 13, 25, 49, 91, 170, 309, 558, 992, 1752, 3062, 5317, 9166, 15712, 26784, 45447, 76775, 129203, 216662, 362177, 603671, 1003566, 1664389, 2754382, 4549207, 7500096, 12344840, 20288723, 33298979, 54584077, 89373081, 146182754 (list; graph; listen)
OFFSET

1,2

REFERENCES

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

R. P. Stanley, A Fibonacci lattice, Fib. Quart., 13 (1975), 215-232.

R. P. Stanley, Ordered structures and partitions, Memoirs of the Amer. Math. Soc., no. 119 (1972).

FORMULA

G.f. = (1-x)^5/Product(1-x-x^i+x^(1+2*i), i=1..5)-1. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 19 2004

MAPLE

G:=(1-x)^5/Product(1-x-x^i+x^(1+2*i), i=1..5)-1: Gser:=series(G, x=0, 39): seq(coeff(Gser, x^n), n=1..37); (Deutsch)

CROSSREFS

Sequence in context: A047194 A048039 A131913 this_sequence A005407 A005116 A121349

Adjacent sequences: A005403 A005404 A005405 this_sequence A005407 A005408 A005409

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 19 2004

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Last modified December 3 22:15 EST 2009. Contains 170310 sequences.


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