OFFSET
0,3
COMMENTS
p divides a(p-1) for prime p>3.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..190
FORMULA
MATHEMATICA
Join[{0}, Table[((2n)^(2n)-1)/(4n^2-1), {n, 1, 20}]]
PROG
(PARI) A128542(n)=((n+=n)^n-1)/(n^2-1) \\ M. F. Hasler, Oct 31 2014
(Magma) [0] cat [((2*n)^(2*n)-1)/(4*n^2 -1): n in [1..20]]; // G. C. Greubel, Jul 11 2019
(Sage) [0]+[((2*n)^(2*n)-1)/(4*n^2 -1) for n in (1..20)] # G. C. Greubel, Jul 11 2019
(GAP) Concatenation([0], List([1..20], n-> ((2*n)^(2*n)-1)/(4*n^2 -1) )); # G. C. Greubel, Jul 11 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, May 08 2007
EXTENSIONS
a(0)=0 added by M. F. Hasler, Oct 31 2014
STATUS
approved