|
%I #23 Jul 05 2022 03:27:30
%S 2,6,30,90,1530,16830,218790,9407970,2417848290,137817352530,
%T 28252557268650,19296496614487950,4650455684091595950,
%U 12700394473254148539450,41619192688853844763777650,13775952780010622616810402150,902834617343556174437903325704550
%N a(n) = LCM_{k=0..n} (2^k + 1).
%F a(n) = lcm(2, 3, 5, ..., 2^n + 1).
%F Product_{k=1..n} cyclotomic(2*k-2, 2). - _Vladeta Jovovic_, Apr 05 2004
%e a(3) = lcm(2, 3, 5) = 30.
%t 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 *)
%o (PARI) a(n) = {ret = 1; for (k=0, n, ret = lcm(ret, 2^k+1)); return(ret);} \\ _Michel Marcus_, May 24 2013
%o (Python)
%o from math import lcm
%o from itertools import accumulate
%o def aupton(nn): return list(accumulate((2**k+1 for k in range(nn+1)), lcm))
%o print(aupton(16)) # _Michael S. Branicky_, Jul 04 2022
%Y Cf. A034268.
%Y Cf. A019320.
%K nonn
%O 0,1
%A _Jeffrey Shallit_, Apr 20 2000
%E More terms from _Harvey P. Dale_, Aug 04 2017
|
