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”).

A053573
a(n) = 5*a(n-1) + 14*a(n-2), a(0)=1, a(1)=5.
4
1, 5, 39, 265, 1871, 13065, 91519, 640505, 4483791, 31386025, 219703199, 1537920345, 10765446511, 75358117385, 527506838079, 3692547833785, 25847834902031, 180934844183145, 1266543909544159, 8865807366284825, 62060651565042351
OFFSET
0,2
REFERENCES
A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 189, 194-196.
F. P. Muga II, Extending the Golden Ratio and the Binet-de Moivre Formula, March 2014; Preprint on ResearchGate.
FORMULA
a(n) = (7^(n+1) - (-2)^(n+1))/9.
a(n) = 5*a(n-1) + 14*a(n-2), with a(0)=1, a(1)=5.
G.f.: 1/(1-5*x-14*x^2). - Zerinvary Lajos, Apr 24 2009
E.g.f.: (7*exp(7*x) - 2*exp(-2*x))/9. - G. C. Greubel, May 16 2019
MATHEMATICA
LinearRecurrence[{5, 14}, {1, 5}, 30] (* Harvey P. Dale, May 29 2017 *)
PROG
(Sage) [lucas_number1(n, 5, -14) for n in range(1, 16)] # Zerinvary Lajos, Apr 24 2009
(PARI) a(n)=n++; (7^n -(-2)^n)/9 \\ Charles R Greathouse IV, Jun 11 2011
(Magma) [(7^(n+1) -(-2)^(n+1))/9: n in [0..30]]; // G. C. Greubel, May 16 2019
(GAP) List([0..30], n-> (7^(n+1) -(-2)^(n+1))/9) # G. C. Greubel, May 16 2019
CROSSREFS
Cf. A090409 (binom. transf.)
Sequence in context: A218918 A075135 A202391 * A003482 A221357 A201442
KEYWORD
easy,nonn
AUTHOR
Barry E. Williams, Jan 18 2000
STATUS
approved