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A073371 Convolution of A001045(n+1) (generalized (1,2)-Fibonacci), n>=0 with itself. 13
1, 2, 7, 16, 41, 94, 219, 492, 1101, 2426, 5311, 11528, 24881, 53398, 114083, 242724, 514581, 1087410, 2291335, 4815680, 10097401, 21126862, 44117867, 91963996, 191384541, 397682154, 825190479, 1710033272, 3539371201, 7317351686 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

PSumSIGN transform of A045883(n-1). - Michael Somos, Jul 10 2003

Numbers of the form ((6n + 4)/27)2^(n) + ((-1)^(n - 1) )(3n + 4)/27. - Artur Jasinski (grafix(AT)csl.pl), Feb 09 2007

REFERENCES

Bosma W. 2001. Signed bits and fast exponentiation. J. Th. Nombres de Bordeaux Vol.13, Fasc. 1

LINKS

Bosma W. Signed bits and fast exponentiation.

FORMULA

a(n)=sum(b(k)*b(n-k), k=0..n) with b(k) := A001045(k+1).

a(n)=sum((n-k+1)*binomial(n-k, k)*2^k, k=0..floor(n/2)).

a(n)= ((n+1)*U(n+1)+2*2*(n+2)*U(n))/9 with U(n) := A001045(n+1), n>=0.

G.f.: 1/(1-(1+2*x)*x)^2.

G.f.: 1/((1+x)(1-2x))^2. a(n)=((5+3n)2^(n+2)+(7+3n)(-1)^n)/27.

a(n) = ((6n + 4)/27)2^(n) + ((-1)^(n - 1) )(3n + 4)/27 - Artur Jasinski (grafix(AT)csl.pl), Feb 09 2007

MATHEMATICA

Table[((6n + 4)/27)2^(n) + ((-1)^(n - 1) )(3n + 4)/27, {n, 1, 100}] - Artur Jasinski (grafix(AT)csl.pl), Feb 09 2007

PROG

(PARI) a(n)=if(n<-3, 0, ((5+3*n)*2^(n+2)+(7+3*n)*(-1)^n)/27)

CROSSREFS

Second (m=1) column of triangle A073370.

Cf. A127976.

Sequence in context: A093971 A065497 A131727 * A113224 A178945 A026571

Adjacent sequences:  A073368 A073369 A073370 * A073372 A073373 A073374

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Aug 2, 2002

EXTENSIONS

Edited by N. J. A. Sloane (njas(AT)research.att.com) at the suggestion of Andrew Plewe, Jun 08 2007

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Last modified February 16 04:47 EST 2012. Contains 205860 sequences.