OFFSET
0,2
COMMENTS
For the denominators see A285060.
This gives one third of the numerators of the z-sequence for the Sheffer triangle (exp(3*x), exp(4*x) - 1) shown in A225467. For the notion and use of a- and z- sequences for Sheffer triangles see the W. Lang link under A006232, also for references. The a-sequence of this Sheffer triangle is given by 4*A006232/A006233.
For the nontrivial recurrence of {3^n} given by the z-sequence for the m = 0 column of the triangle A225467 see the example for n = 3 below.
FORMULA
E.g.f.: (4/(3*log(1+x)))*(1 - 1/(1+x)^(3/4)) for the rational sequence a(n)/A285060(n), n >= 0.
EXAMPLE
CROSSREFS
KEYWORD
sign,frac,easy
AUTHOR
Wolfdieter Lang, Apr 13 2017
STATUS
approved