login
A062971
a(n) = (2*n)^n.
20
1, 2, 16, 216, 4096, 100000, 2985984, 105413504, 4294967296, 198359290368, 10240000000000, 584318301411328, 36520347436056576, 2481152873203736576, 182059119829942534144, 14348907000000000000000, 1208925819614629174706176, 108428035605965932354207744
OFFSET
0,2
COMMENTS
Shift n^n left n bits.
Also the number of input-closed output-Boolean Moore machines on n states. - David Spivak, Feb 14 2020
LINKS
FORMULA
E.g.f.: -(2*x*e^(-W(-2*x)))/(W(-2*x)*(W(-2*x)+1)), W(x) is Lambert's function. - Vladimir Kruchinin, May 09 2013
E.g.f.: 1/(1 + LambertW(-2*x)). - Vaclav Kotesovec, Dec 21 2014
Limit_{n->oo} a(n+1)/(n*a(n)) = 2*e. - Stefano Spezia, Mar 13 2023
EXAMPLE
n=3: 3^3 shifted three bits to the left is 216 because 3^3 in binary is: [1, 1, 0, 1, 1] and 216 in binary is: [1, 1, 0, 1, 1, 0, 0, 0].
MAPLE
a:= n-> (2*n)^n: seq(a(n), n=0..15); # Zerinvary Lajos, Jan 01 2009
MATHEMATICA
Join[{1}, Table[(2*n)^n, {n, 1, 50}]] (* G. C. Greubel, Nov 10 2017 *)
PROG
(PARI) for(n=0, 20, print1(shift(n^n, n), ", "))
CROSSREFS
Column k=1 of A246070.
Cf. A019762 (2*e).
Sequence in context: A114531 A365585 A012056 * A267782 A012164 A264543
KEYWORD
easy,nonn
AUTHOR
Jason Earls, Jul 23 2001
EXTENSIONS
New description from Vladeta Jovovic, Mar 08 2003
STATUS
approved