

A050923


a(n) = 2^(n!).


11




OFFSET

0,1


COMMENTS

For n > 0, every nfold repetition of a(n) is a "powerful" arithmetic progression with difference 0; e.g., for n = 4 we get a(4) = 16777216 and in the generated repeating sequence of length 4 the kth term is a kth power (1 <= k <= n): 16777216 = 16777216^1, 16777216 = 4096^2, 16777216 = 256^3, 16777216 = 64^4.  Martin Renner, Aug 16 2017


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..6
Index to divisibility sequences


FORMULA

a(n) = a(n1)^n, a(0)=2.
a(n) = A000079(A000142(n)).


MATHEMATICA

a=2; lst={}; Do[a=a^n; AppendTo[lst, a], {n, 1, 7}]; lst (* Vladimir Joseph Stephan Orlovsky, May 26 2009 *)
Table[2^n!, {n, 0, 9}] (* Vincenzo Librandi, Dec 16 2012 *)


PROG

(MAGMA) [2^Factorial(n): n in [0..8]]; // Vincenzo Librandi, Dec 16 2012
(Maxima) makelist(2^(n!), n, 0, 5); /* Martin Ettl, Dec 27 2012 */
(PARI) a(n)=2^n! \\ Charles R Greathouse IV, Aug 16 2017


CROSSREFS

Cf. A000079, A000142, A100731.
Sequence in context: A295580 A177956 A178981 * A326960 A067700 A270554
Adjacent sequences: A050920 A050921 A050922 * A050924 A050925 A050926


KEYWORD

easy,nonn


AUTHOR

Klaus Strassburger (strass(AT)ddfi.uniduesseldorf.de), Dec 30 1999


STATUS

approved



