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A062206 a(n) = n^(2n). 19
1, 1, 16, 729, 65536, 9765625, 2176782336, 678223072849, 281474976710656, 150094635296999121, 100000000000000000000, 81402749386839761113321, 79496847203390844133441536, 91733330193268616658399616009 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

a(n) is also the number of sequences of length 2n on n symbols. - Washington Bomfim, Oct 06 2009

LINKS

Harry J. Smith, Table of n, a(n) for n = 0..100

FORMULA

a(n) = A000312(n)^2.

(-1)^n*determinant of the 2n X 2n matrix M_(i, j) = i+j if (i + j) is a multiple of n, M_(i, j) = 1 otherwise. - Benoit Cloitre, Aug 06 2003

a(n) = A155955(n,n) = A000290(A000312(n)). - Reinhard Zumkeller, Jan 31 2009

a(n) = n! * [x^n] 1/(1 + LambertW(-n*x)). - Ilya Gutkovskiy, Oct 03 2017

MATHEMATICA

f[n_]:=n^(2*n); Join[{1}, f[Range[20]]] (* Vladimir Joseph Stephan Orlovsky, Feb 19 2011 *)

PROG

(PARI) { for (n=0, 100, write("b062206.txt", n, " ", n^(2*n)) ) } \\ Harry J. Smith, Aug 02 2009

CROSSREFS

Cf. A062207.

Cf. A155957.

Cf. A000312, A085741, A212333.

Column k=0 of A245910 and A245980.

Sequence in context: A220809 A221023 A171736 * A209537 A086701 A218297

Adjacent sequences:  A062203 A062204 A062205 * A062207 A062208 A062209

KEYWORD

easy,nonn

AUTHOR

Jason Earls, Jun 13 2001

EXTENSIONS

Initial term corrected by Reinhard Zumkeller, Jan 30 2009

STATUS

approved

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Last modified February 20 04:19 EST 2018. Contains 299358 sequences. (Running on oeis4.)