OFFSET
0,1
COMMENTS
LINKS
FORMULA
a(n) = 2*(4*3^n-1).
G.f.: 2*(3-x)/((1-x)*(1-3*x)).
MATHEMATICA
NestList[3#+4&, 6, 30] (* Harvey P. Dale, Aug 25 2019 *)
PROG
(PARI) {m=25; v=concat([6], vector(m-1)); for(n=2, m, v[n]=3*v[n-1]+4); v}
CROSSREFS
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Dec 10 2009
STATUS
approved