A032778 Numbers k such that k*(k+1)*(k+2)*...*(k+7) / (k+(k+1)+(k+2)+...+(k+7)) is an integer.

0, 1, 4, 7, 9, 14, 19, 21, 28, 34, 49, 70, 84, 109, 119, 154, 217, 259, 364, 609, 784, 1099, 1834, 5509

Offset: 1

Author

Patrick De Geest, May 15 1998

Keywords

• nonn
• fini
• full

Comments

(d-7)/2 where d >= 7 is a divisor of 11025, so sequence is finite. - Robert Israel, Jul 12 2018

Crossrefs

Cf. A032777, A032779.

Programs

Mathematica

Select[Range[0, 300], IntegerQ[Times@@Range[#, # + 7] / Total[Range[#, # + 7]]] &] (* Vincenzo Librandi, Jul 13 2018 *)

Extensions

Offset changed by Robert Israel, Jul 12 2018