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”).

A146523
Binomial transform of A010685.
9
1, 5, 10, 20, 40, 80, 160, 320, 640, 1280, 2560, 5120, 10240, 20480, 40960, 81920, 163840, 327680, 655360, 1310720, 2621440, 5242880, 10485760, 20971520, 41943040, 83886080, 167772160, 335544320, 671088640, 1342177280, 2684354560, 5368709120, 10737418240
OFFSET
0,2
COMMENTS
Linked to A029609 by a Catalan transform.
Hankel transform is (1, -15, 0, 0, 0, 0, 0, 0, 0, ...).
FORMULA
a(n) = 5*2^(n-1) for n >= 1, a(0) = 1.
a(n) = Sum_{k=0..n} A109466(n,k)*A029609(k).
a(n) = A084215(n+1) = A020714(n-1), n > 0. - R. J. Mathar, Nov 02 2008
G.f.: (1 + 3*x)/(1 - 2*x). - Vladimir Joseph Stephan Orlovsky, Jun 21 2011
G.f.: G(0), where G(k)= 1 + 3*x/(1 - 2*x/(2*x + 3*x/G(k+1) )); (continued fraction). - Sergei N. Gladkovskii, Jul 03 2013
E.g.f.: (5*exp(2*x) - 3)/2. - Stefano Spezia, Feb 20 2023
MATHEMATICA
CoefficientList[Series[(1+3x)/(1-2x), {x, 0, 50}], x] (* Vladimir Joseph Stephan Orlovsky, Jun 21 2011 *)
Join[{1}, 5*2^(Range[40] -1)] (* G. C. Greubel, Nov 23 2021 *)
PROG
(PARI) a(n)=if(n, 5<<(n-1), 1) \\ Charles R Greathouse IV, Jan 17 2012
(Sage) [1]+[5*2^(n-1) for n in (1..50)] # G. C. Greubel, Nov 23 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Philippe Deléham, Oct 30 2008
STATUS
approved