OFFSET
0,2
COMMENTS
Hankel transform of A128750. Satisfies (4,0) Somos-4 recurrence 4*a(n-1)*a(n-3)/a(n-4) = a(n),n>3.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..99
FORMULA
2^A007980.
a(n) = a(-1-n) for all n in Z. - Michael Somos, Aug 14 2018
MATHEMATICA
Table[2^Ceiling[(n(n+1))/3], {n, 0, 20}] (* Harvey P. Dale, Sep 25 2013 *)
PROG
(PARI) vector(20, n, n--; 2^ceil(n*(n+1)/3)) \\ G. C. Greubel, Aug 14 2018
(Magma) [2^Ceiling((n(n+1))/3): n in [0..20]]; // G. C. Greubel, Aug 14 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul Barry, Jan 08 2011
STATUS
approved