A093462 a(1)=1, a(n) = 2(n^(n-1)-1)/(n-1)^2.

1, 2, 4, 14, 78, 622, 6536, 85598, 1345210, 24691358, 518748492, 12281130094, 323584515590, 9393074239694, 297887000259088, 10248191152060862, 380165561528647410, 15127415638330079806, 642761421592044700820

Offset

1,2

Links

Table of n, a(n) for n=1..19.

Mathematica

Insert[Table[2*(n^(n - 1) - 1)/(n - 1)^2, {n, 2, 20}], 1, 1] (* Stefan Steinerberger, Mar 18 2006 *)

Crossrefs

Cf. A093460, A093461.

Sequence in context: A075098 A340909 A052856 * A302136 A181080 A166894

Adjacent sequences: A093459 A093460 A093461 * A093463 A093464 A093465

Keyword

nonn

Author

Amarnath Murthy, Apr 05 2004

Extensions

Corrected and extended by Stefan Steinerberger, Mar 18 2006

Status

approved