A093147 Third binomial transform of Pell(3n+1).

1, 15, 250, 4250, 72500, 1237500, 21125000, 360625000, 6156250000, 105093750000, 1794062500000, 30626562500000, 522828125000000, 8925234375000000, 152363281250000000, 2601003906250000000, 44401914062500000000

Offset

0,2

Links

Table of n, a(n) for n=0..16.

Index entries for linear recurrences with constant coefficients, signature (20,-50).

Formula

G.f.: (1-5*x)/(1 - 20*x + 50*x^2);

a(n) = ((1 + sqrt(2))*(10 + 5*sqrt(2))^n - (1 - sqrt(2))*(10-5*sqrt(2))^n)/(2*sqrt(2)).

Crossrefs

Cf. A000129, A093144, A093146.

Sequence in context: A218806 A285395 A331493 * A218192 A066410 A370317

Adjacent sequences: A093144 A093145 A093146 * A093148 A093149 A093150

Keyword

easy,nonn

Author

Paul Barry, Mar 26 2004

Status

approved