|
|
A120621
|
|
Least positive k such that !n + k is prime, where !n is left factorial.
|
|
1
|
|
|
2, 1, 1, 1, 1, 3, 3, 3, 9, 3, 7, 9, 7, 13, 49, 27, 9, 37, 19, 33, 7, 93, 103, 9, 73, 27, 13, 27, 165, 49, 39, 93, 97, 27, 37, 39, 135, 7, 193, 249, 39, 103, 13, 33, 213, 129, 33, 13, 39, 115, 187, 19, 7, 387, 19, 489, 303, 63, 33, 235, 297, 495, 657, 465, 235, 193, 369, 129
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
|
|
MATHEMATICA
|
a[n_] := Module[{k = 1, lf = Sum[i!, {i, 0, n - 1}]}, While[!PrimeQ[lf + k], k++]; k]; Array[a, 100, 0] (* Amiram Eldar, Dec 24 2019 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|