login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A163474
a(n) = 16*a(n-1) - 61*a(n-2) for n > 1; a(0) = 3, a(1) = 27.
3
3, 27, 249, 2337, 22203, 212691, 2048673, 19804617, 191904819, 1862395467, 18092133513, 175868012721, 1710268059243, 16636340171907, 161855091136689, 1574864707700697, 15324674763873123, 149128049052227451
OFFSET
0,1
COMMENTS
Binomial transform of A163473. Inverse binomial transform of A163475.
FORMULA
a(n) = ((3+sqrt(3))*(8+sqrt(3))^n + (3-sqrt(3))*(8-sqrt(3))^n)/2.
G.f.: (3-21*x)/(1-16*x+61*x^2).
E.g.f.: exp(8*x)*( 3*cosh(sqrt(3)*x) + sqrt(3)*sinh(sqrt(3)*x) ). - G. C. Greubel, Jul 26 2017
MATHEMATICA
LinearRecurrence[{16, -61}, {3, 27}, 50] (* G. C. Greubel, Jul 26 2017 *)
PROG
(Magma) [ n le 2 select 24*n-21 else 16*Self(n-1)-61*Self(n-2): n in [1..18] ];
(PARI) x='x+O('x^50); Vec((3-21*x)/(1-16*x+61*x^2)) \\ G. C. Greubel, Jul 26 2017
CROSSREFS
Sequence in context: A037770 A037658 A370271 * A235373 A361895 A279658
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Aug 11 2009
STATUS
approved