OFFSET
1,2
COMMENTS
Also continued fraction expansion of (9+sqrt(229))/74. - Bruno Berselli, Sep 09 2011
LINKS
Eric Weisstein's World of Mathematics, Waring's Problem
Index entries for linear recurrences with constant coefficients, signature (1).
FORMULA
A061439(n) + A181375(n) + A181377(n) + A181379(n) + A181381(n) + A181400(n) + A181402(n) + a(n) + A130130(n) = A002283(n).
a(n) = 15 for n > 2. - Charles R Greathouse IV, Sep 09 2011
G.f.: 3*x^2*(1+4*x)/(1-x). - Bruno Berselli, Sep 09 2011
E.g.f.: 3*(5*(exp(x) - 1 - x) - 2*x^2). - Stefano Spezia, May 21 2024
MATHEMATICA
PadRight[{0, 3}, 100, 15] (* Paolo Xausa, May 24 2024 *)
PROG
(PARI) a(n)=if(n>2, 15, 3*n-3) \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Martin Renner, Jan 28 2011
EXTENSIONS
a(5)-a(7) from Lars Blomberg, May 04 2011
STATUS
approved