OFFSET
1,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = 1 for n>1 in A272934. - Michel Marcus, Jul 04 2017
EXAMPLE
a(6) = 2**6 mod (6*7/2) = 64 mod 21 = 1.
MAPLE
seq(2^n mod n*(n+1)/2, n=1..100); # Robert Israel, Jul 04 2017
MATHEMATICA
Table[Mod[2^n, n (n + 1)/2], {n, 66}] (* Michael De Vlieger, Jul 04 2017 *)
PowerMod[2, #, (#(#+1))/2]&/@Range[70] (* Harvey P. Dale, Oct 12 2018 *)
PROG
(Python)
for n in range(1, 99): print(str(int(2**n % (n*(n+1)/2))), end=', ')
(PARI) a(n) = lift(Mod(2, n*(n+1)/2)^n); \\ Michel Marcus, Jul 04 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Alex Ratushnyak, Jul 04 2017
STATUS
approved