OFFSET
0,1
FORMULA
a(n) = lcm(2, 3, 5, ..., 2^n + 1).
Product_{k=1..n} cyclotomic(2*k-2, 2). - Vladeta Jovovic, Apr 05 2004
EXAMPLE
a(3) = lcm(2, 3, 5) = 30.
MATHEMATICA
Module[{nn=20, c}, c=Table[2^n+1, {n, 0, nn}]; Table[LCM@@Take[c, n], {n, nn}]] (* Harvey P. Dale, Aug 04 2017 *)
PROG
(PARI) a(n) = {ret = 1; for (k=0, n, ret = lcm(ret, 2^k+1)); return(ret); } \\ Michel Marcus, May 24 2013
(Python)
from math import lcm
from itertools import accumulate
def aupton(nn): return list(accumulate((2**k+1 for k in range(nn+1)), lcm))
print(aupton(16)) # Michael S. Branicky, Jul 04 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeffrey Shallit, Apr 20 2000
EXTENSIONS
More terms from Harvey P. Dale, Aug 04 2017
STATUS
approved