login
A126884
a(n) = (2^0)*(2^1)*(2^2)*(2^3)...(2^n)+1 = 2^T_n+1 (cf. A000217).
1
2, 3, 9, 65, 1025, 32769, 2097153, 268435457, 68719476737, 35184372088833, 36028797018963969, 73786976294838206465, 302231454903657293676545, 2475880078570760549798248449, 40564819207303340847894502572033, 1329227995784915872903807060280344577, 87112285931760246646623899502532662132737
OFFSET
0,1
COMMENTS
For n>1 every odd/even pair share at least one factor.
FORMULA
a(n) = 2^A000217(n)+1. - Michel Marcus, Jul 16 2013
a(n) = A006125(n+1)+1. - Alois P. Heinz, Jun 20 2020
MAPLE
a:= n-> 2^(n*(n+1)/2)+1:
seq(a(n), n=0..16); # Alois P. Heinz, Jun 20 2020
MATHEMATICA
Table[Times@@(2^Range[0, n])+1, {n, 0, 20}] (* Harvey P. Dale, Aug 10 2021 *)
PROG
(PARI) a(n) = prod(k=0, n, 2^k) + 1 \\ Michel Marcus, Jul 16 2013
CROSSREFS
Sequence in context: A181273 A270394 A120032 * A054544 A269993 A132537
KEYWORD
nonn,easy
AUTHOR
Marco Matosic, Dec 29 2006
EXTENSIONS
a(11) corrected and a(14-16) from Georg Fischer, Jun 20 2020
STATUS
approved