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A288717
Primes of the form k!7+1, where k!7 is the septuple factorial number (A114799).
1
2, 3, 5, 7, 19, 31, 61, 79, 12241, 19801, 29641, 76561, 379441, 2016841, 2756161, 1838865601, 4150656721, 337767408001, 956960801281, 21617114112001, 1534815101952001, 9590944392057601, 30891838760640001, 119715577952256001, 767275551364608001
OFFSET
1,1
LINKS
MATHEMATICA
MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 7] + 1, {i, 0, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n, 1, -7]+1, {n, 100}], PrimeQ] (* Harvey P. Dale, Dec 23 2022 *)
CROSSREFS
Cf. A156165.
Sequence in context: A087562 A375095 A154525 * A144561 A215156 A065724
KEYWORD
nonn
AUTHOR
Robert Price, Jun 13 2017
STATUS
approved