a(n) is the least prime factor of the alternating factorial n! - (n-1)! + (n-2)! - ... 1! for n > 2; a(1) = a(2) = 1.
A359808
a(n) is the least prime factor of the alternating factorial n! - (n-1)! + (n-2)! - ... 1! for n > 2; a(1) = a(2) = 1.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =19a(4) =101a(5) =619a(6) =4421a(7) =35899a(8) =79a(9) =3301819a(10) =13a(11) =29a(12) =47a(13) =23a(15) =53a(16) =47a(17) =2683a(19) =8969a(20) =113a(21) =79a(22) =85439a(23) =12203a(24) =59a(25) =1657a(26) =127a(27) =61a(28) =661a(29) =47a(30) =173183a(31) =1117
External references
- oeis: A359808