|
|
A260982
|
|
a(n) = (2^(2^(n+1)) + 2^(2^n) + 1)/21.
|
|
0
|
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
Table of n, a(n) for n=1..7.
|
|
FORMULA
|
a(n) = A001576(2^n)/21. - Michel Marcus, Aug 14 2015
|
|
EXAMPLE
|
a(2) = (2^(2^(2+1)) + 2^(2^2) + 1)/21 = 13.
|
|
MATHEMATICA
|
Table[(2^(2^(n + 1)) + 2^(2^n) + 1)/21, {n, 1, 10}] (* Vincenzo Librandi, Aug 08 2015 *)
|
|
PROG
|
(PARI) first(m)=my(v=vector(m, t, (2^(2^(t+1))+2^(2^t)+1)/21)); v; /* Anders Hellström, Aug 07 2015 */
(MAGMA) [(2^(2^(n+1)) + 2^(2^n) + 1)/21: n in [1..10]]; // Vincenzo Librandi, Aug 08 2015
|
|
CROSSREFS
|
Cf. A001576 (1^n + 2^n + 4^n).
Sequence in context: A208315 A296174 A220642 * A159357 A221885 A134159
Adjacent sequences: A260979 A260980 A260981 * A260983 A260984 A260985
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
Marco Ripà, Aug 07 2015
|
|
STATUS
|
approved
|
|
|
|