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A127221 2^n*pentanacci(n) or (2^n)*A0234248(n). +0
3
2, 12, 56, 240, 992, 3648, 14464, 57088, 224768, 883712, 3471360, 13651968, 53682176, 211075072, 829915136, 3263102976, 12830244864, 50447253504, 198353354752, 779904614400 (list; graph; listen)
OFFSET

1,1

FORMULA

a(n) = Trace of matrix [({{2,2,2,2,0},{2,0,0,0,0},{0,2,0,0,0),{0,0,2,0,0},{0,0,0,2,0})^n] a(n) = 2^n Trace of matrix [({{1,1,1,1,1},{1,0,0,0,0},{0,1,0,0,0},{0,0,1,0,0},{0,0,0,1,0)^n]

MATHEMATICA

Table[Tr[MatrixPower[2*{{1, 1, 1, 1, 1}, {1, 0, 0, 0, 0}, {0, 1, 0, 0, 0}, {0, 0, 1, 0, 0}, {0, 0, 0, 1, 0}}, x]], {x, 1, 20}]

CROSSREFS

Cf. A087131, A127210, A127211, A127212, A127213, A127214, A127216, A001648, A127220, A127222.

Sequence in context: A122229 A127216 A006659 this_sequence A020522 A037130 A078543

Adjacent sequences: A127218 A127219 A127220 this_sequence A127222 A127223 A127224

KEYWORD

nonn

AUTHOR

Artur Jasinski (grafix(AT)csl.pl), Jan 09 2007

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.


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