A082952 Smaller of the two factors of the n-th semiprime number of the form m!+1.
5, 11, 7, 71, 61, 11, 83, 23, 71, 20639383, 811, 401, 1697, 29, 67411, 14029308060317546154181, 12893, 12318573951317236818169524329, 79, 16567, 6653, 293, 229758023927584562777368125832724248866067995638905559798117
Offset: 1
Keywords
Examples
a(3)=7 because A078778(3)!+1=6!+1=721=7*103
Links
- Paul Leyland, Tables of factors of N!+1 and N!-1.
- Hisanori Mishima, n! + 1 (n = 1 to 100).
Programs
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Mathematica
FactorInteger[#][[1,1]]&/@Select[Range[50]!+1,PrimeOmega[#]==2&] (* The program generates the first 17 terms of the sequence. To generate more, increase the Range constant but the program may take a long time to run.*) (* Harvey P. Dale, Dec 11 2023 *)
Formula
Numbers p such that p*q=A078778(n)!+1, p, q prime, p