A006236 a(n) = n^(n-2)*(n+2)^(n-1). (Formerly M3698)

1, 4, 75, 3456, 300125, 42467328, 8931928887, 2621440000000, 1025271882697689, 515978035200000000, 325063112540091870659, 250738401558910243700736, 232526248038920243408203125, 255326682647558617373989666816, 327696095670976278474202880859375, 486146690661928563361690196851556352

Offset

1,2

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

T. D. Noe, Table of n, a(n) for n = 1..100

Germain Kreweras, Complexité et circuits Eulériens dans les sommes tensorielles de graphes, J. Combin. Theory, B 24 (1978), 202-212.

Mathematica

Table[n^(n - 2)*(n + 2)^(n - 1), {n, 20}] (* T. D. Noe, May 29 2012 *)

Crossrefs

Sequence in context: A006412 A206456 A137220 * A374884 A120248 A191505

Adjacent sequences: A006233 A006234 A006235 * A006237 A006238 A006239

Keyword

nonn

Author

N. J. A. Sloane

Extensions

Clarified definition and more terms from N. J. A. Sloane, May 27 2012

Status

approved