A004785 5!(2n-6)!/n!(n-1)! is an integer.

3, 5, 6, 101, 211, 461, 552, 562, 852, 947, 990, 1223, 1432, 1451, 1458, 1506, 1600, 1626, 1892, 2015, 2069, 2147, 2185, 2333, 2480, 2481, 2666, 2994, 3011, 3017, 3356, 3418, 3433, 3442, 3478, 3479, 3485, 3521, 3554, 3566, 3571, 3620, 3628

Offset

1,1

Links

Table of n, a(n) for n=1..43.

Mathematica

Select[Range[4000], IntegerQ[5!(2#-6)!/(#!(#-1)!)]&] (* Harvey P. Dale, Jun 05 2011 *)

Crossrefs

Sequence in context: A137082 A242501 A099414 * A099744 A024601 A173013

Adjacent sequences: A004782 A004783 A004784 * A004786 A004787 A004788

Keyword

nonn

Author

R. K. Guy

Extensions

3 and 5 added to the sequence by Harvey P. Dale, Jun 05 2011

Status

approved