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A006898 a(n) = Sum_{k=0..n} C(n,k)*2^(k*(k+1)/2).
(Formerly M2958)
2
1, 3, 13, 95, 1337, 38619, 2310533, 283841911, 70927591153, 35812691480115, 36383765777442685, 74185239630793429775, 303119284294591169426729, 2479814853198140771706795531, 40599509058360322571947638063605 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Number of hierarchical quadratic models on n factors (first differences of A006896).

REFERENCES

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

LINKS

Table of n, a(n) for n=0..14.

PROG

(PARI) a(n)=sum(k=0, n, binomial(n, k)*2^(k*(k+1)/2)) - Paul D. Hanna, Apr 10 2009

CROSSREFS

Cf. A006896, A135748.

Sequence in context: A243243 A274052 A183283 * A277492 A275528 A129375

Adjacent sequences:  A006895 A006896 A006897 * A006899 A006900 A006901

KEYWORD

nonn

AUTHOR

Colin Mallows

EXTENSIONS

Formula and more terms from Vladeta Jovovic, Sep 20 2003

Edited by N. J. A. Sloane, Apr 12 2009 at the suggestion of Vladeta Jovovic

STATUS

approved

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Last modified November 18 19:06 EST 2017. Contains 294894 sequences.