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A003470
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a(n) = n*a(n-1) - a(n-2) + 1 + (-1)^n.
(Formerly M2759)
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4
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1, 1, 3, 8, 31, 147, 853, 5824, 45741, 405845, 4012711, 43733976, 520795003, 6726601063, 93651619881, 1398047697152, 22275111534553, 377278848390249, 6768744159489931, 128228860181918440, 2557808459478878871
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| Row sums of A086764. - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Apr 27 2004
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REFERENCES
| N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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FORMULA
| Diagonal sums of reverse of permutation triangle A008279. a(n)=sum{k=0..floor(n/2), (n-k)!/k!}. - Paul Barry (pbarry(AT)wit.ie), May 12 2004
a(n)=sum{k=0..floor(n/2), C(n-k,k)*(n-2k)!}. - Paul Barry (pbarry(AT)wit.ie) Dec 15 2010.
G.f.: 1/(1-x^2-x/(1-x/(1-x^2-2x/(1-2x/(1-x^2-3x/(1-3x/(1-x^2-4x/(1-4x/(1-.... (continued fraction);
G.f.: 1/(1-x-x^2-x^2/(1-3x-x^2-4x^2/(1-5x-x^2-9x^2/(1-7x-x^2-16x^2/(1-... (continued fraction). - Paul Barry (pbarry(AT)wit.ie) Dec 15 2010.
G.f.: hypergeom([1,1],[],x/(1-x^2))/(1-x^2) - Mark van Hoeij, Nov 08 2011
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CROSSREFS
| Cf. A072374.
Sequence in context: A148901 A148902 A108492 * A176304 A180385 A148903
Adjacent sequences: A003467 A003468 A003469 * A003471 A003472 A003473
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KEYWORD
| nonn,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), jr
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EXTENSIONS
| More terms from Gabriel Cunningham (gcasey(AT)mit.edu), Oct 25 2004
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