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A289757
Primes of the form k!7-1, where k!7 is the septuple factorial number (A114799).
1
2, 3, 5, 7, 17, 29, 43, 59, 97, 509, 1559, 12239, 198719, 379439, 633599, 1136678399, 33739804799, 99298742399, 1990648483199, 59126328543388935628799, 3797826416991538753535999, 2409161546475779555007420356689919999, 9325555101161759039183007326207999999
OFFSET
1,1
LINKS
MATHEMATICA
MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 7] - 1, {i, 2, 100}], PrimeQ[#]&]
CROSSREFS
Cf. A156167.
Sequence in context: A356475 A178382 A360591 * A030480 A048418 A074788
KEYWORD
nonn
AUTHOR
Robert Price, Jul 11 2017
STATUS
approved