A275276 a(n) = n! - p, where p is the third greatest prime less than n!.

6, 7, 4, 7, 13, 19, 19, 43, 29, 23, 43, 17, 67, 43, 71, 89, 239, 47, 197, 151, 43, 139, 197, 191, 239, 191, 173, 197, 47, 97, 223, 373, 71, 439, 307, 263, 157, 241, 199, 233, 337, 131, 179, 149, 113, 277, 269, 409, 197, 193, 379, 271, 181, 419, 367, 701, 751

Offset

1,1

Comments

Is every term except 4 and 6 a prime?

Links

Clark Kimberling, Table of n, a(n) for n = 1..300

Example

For n = 4, we have n! = 24, so that p = 17, and a(4) = 7.

Mathematica

Table[n! - NextPrime[n!, -3], {n, 1, 150}]

Crossrefs

Cf. A275272, A000040.

Sequence in context: A254374 A019616 A274209 * A073177 A230848 A364356

Adjacent sequences: A275273 A275274 A275275 * A275277 A275278 A275279

Keyword

nonn,easy

Author

Clark Kimberling, Jul 23 2016

Extensions

Name corrected by Pavel Irzhavski, Jul 25 2016

Status

approved