OFFSET
2,3
LINKS
Chai Wah Wu, Table of n, a(n) for n = 2..89
FORMULA
a(n) ~ c * d^(n/2) * r^(n^2/2), where r = A058265 = 1.839286755214161132551852564653286600424178746097592246778758639404203222... is the root of the equation r^3 - r^2 - r - 1 = 0, d = 0.061463687669952618841340986526101395138659648898940720192319213600612851... is the root of the equation -1 + 36*d - 440*d^2 + 1936*d^3 = 0, c = 4.156714772910304733054135311449211887936035199917470476143821433373978333... .
MATHEMATICA
Table[Product[SeriesCoefficient[x^2/(1-x-x^2-x^3), {x, 0, k}], {k, 2, n}], {n, 2, 20}]
PROG
(Python)
A254231_list, a, b, c, d = [1], 0, 0, 1, 1
for _ in range(15):
a, b, c = b, c, a+b+c
d *= c
A254231_list.append(d) # Chai Wah Wu, Jan 27 2015
CROSSREFS
KEYWORD
nonn,changed
AUTHOR
Vaclav Kotesovec, Jan 27 2015
STATUS
approved