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A137361
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Sum_{k <= n/2 } k*binomial(n-2k, 3k+2).
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7
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0, 0, 0, 0, 0, 0, 0, 1, 6, 21, 56, 126, 254, 480, 882, 1617, 2992, 5580, 10410, 19292, 35400, 64343, 116128, 208701, 374226, 670095, 1198164, 2138423, 3808148, 6766089, 11996042, 21229790, 37513896, 66202347, 116692472, 205458357, 361349662, 634845141, 1114205988
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,9
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REFERENCES
| D. E. Knuth, The Art of Computer Programming, Vol. 4A, Section 7.1.4.
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FORMULA
| G.f.: x^7/(x^5+x^3-3*x^2+3*x-1)^2. - Alois P. Heinz, Oct 23 2008
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MAPLE
| a:= n-> (Matrix (10, (i, j)-> if i=j-1 then 1 elif j=1 then [6, -15, 20, -15, 8, -7, 6, -2, 0, -1][i] else 0 fi)^n)[1, 8]:
seq (a(n), n=0..50); # Alois P. Heinz, Oct 23 2008
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CROSSREFS
| Cf. A137356-A137360, A136444.
Sequence in context: A192080 A019500 A100356 * A058484 A145455 A145134
Adjacent sequences: A137358 A137359 A137360 * A137362 A137363 A137364
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KEYWORD
| nonn
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AUTHOR
| D. E. Knuth, Apr 11 2008
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