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A053486 E.g.f.: exp(3x)/(1-x). +0
11
1, 4, 17, 78, 393, 2208, 13977, 100026, 806769, 7280604, 72865089, 801693126, 9620848953, 125072630712, 1751021612937, 26265338542962, 420245459734113, 7144172944620084, 128595113390582001, 2443307155583319486, 48866143115153174121 (list; graph; listen)
OFFSET

0,2

LINKS

J. W. Layman, The Hankel Transform and Some of its Properties, J. Integer Sequences, 4 (2001), #01.1.5.

FORMULA

a(n) is the permanent of the n X n matrix with 4's on the diagonal and 1's elsewhere. a(n) = Sum(k=0..n, A008290(n, k)*4^k). - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Dec 12 2003

a(n) = Sum[(n! / k!) * 3^k {k=0...n}] - Ross La Haye (rlahaye(AT)new.rr.com), Sep 21 2004

a(n)=sum{k=0..n, k!*C(n, k)3^(n-k)}; - Paul Barry (pbarry(AT)wit.ie), Apr 22 2005

MAPLE

restart: G(x):=exp(3*x)/(1-x): g[0]:=G(x): for n from 1 to 20 do g[n]:=diff(g[n-1], x) od: x:=0: seq(g[n], n=0..20); # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 03 2009]

CROSSREFS

Cf. A008290.

Sequence in context: A104455 A123952 A005494 this_sequence A151249 A110307 A089165

Adjacent sequences: A053483 A053484 A053485 this_sequence A053487 A053488 A053489

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Jan 15 2000

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Last modified November 30 13:13 EST 2009. Contains 167758 sequences.


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