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A071921 Square array giving number of unimodal functions [n]->[m] for n>=0, m>=0, with a(0,m)=1 by definition, read by antidiagonals. 1
1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 3, 4, 1, 0, 1, 4, 9, 7, 1, 0, 1, 5, 16, 22, 11, 1, 0, 1, 6, 25, 50, 46, 16, 1, 0, 1, 7, 36, 95, 130, 86, 22, 1, 0, 1, 8, 49, 161, 295, 296, 148, 29, 1, 0, 1, 9, 64, 252, 581, 791, 610, 239, 37, 1, 0 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,8

COMMENTS

If one uses a definition of unimodality that involves universal quantifiers on the domain of a function then a(0,m)=1 a priori.

FORMULA

a(n, m)=1 if n=0, m>=0, a(n, m)=sum_{k=0}^{m-1} binomial(2k+n-1, 2k) otherwise.

CROSSREFS

Sequence in context: A094266 A071569 A118340 * A003992 A171882 A118345

Adjacent sequences:  A071918 A071919 A071920 * A071922 A071923 A071924

KEYWORD

nonn,easy,tabl

AUTHOR

Michele Dondi (bik.mido(AT)tiscalinet.it), Jun 14, 2002

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