A049433
Numbers k such that k! - (k-1)! - 1 is prime.
Original entry on oeis.org
3, 4, 6, 8, 9, 12, 28, 78, 99, 184, 286, 291, 398, 411, 600, 718, 732, 889, 1963, 2240, 2242, 2533, 8800, 11403, 18335, 20277, 21029
Offset: 1
Paul Jobling (paul.jobling(AT)whitecross.com)
6 is a term since 6! - (6-1)! - 1 = 599 is prime.
Corrected offset, edited definition and a(19)-a(24) from
Donovan Johnson, Dec 18 2009
A049984
Primes of the form n! - (n-1)! + 1.
Original entry on oeis.org
2, 5, 19, 97, 601, 35281, 5748019201, 2311256907767808001, 594596384994354462720001, 5382999938946608755288342267304597177897268019200000000001, 136332557214406957166109544809874331662074014454506289616400595025920000000000001
Offset: 1
A090703
Numbers k such that k*k! + 1 is prime.
Original entry on oeis.org
1, 2, 3, 4, 5, 7, 12, 19, 23, 45, 58, 149, 151, 197, 682, 879, 1134, 1906, 6616, 10242, 12015
Offset: 1
mohammed bouayoun (bouyao(AT)wanadoo.fr), Jan 15 2004
3*3! + 1 = 19 and 19 is prime, so 3 is a member.
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Do[If[PrimeQ[n*n! + 1], Print[n]], {n, 0, 2000}] (* Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), May 05 2006 *)
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isok(k) = ispseudoprime(k*k! + 1); \\ Altug Alkan, Mar 22 2018
a(17) from Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), May 05 2006
A245495
Primes of the form n! - (n+1)! + (n+2)! + 1.
Original entry on oeis.org
103, 4441, 36650881, 5787936001, 19702293811201, 1075342687614074880001, 8547762518578406446202880000001, 59043709472234119545920159524322926688993280000000001, 698533028148544417308552639358841460358000936394290829866303488000000000001
Offset: 1
m = 3: m! - (m+1)! + (m+2)! + 1 = 103, which is prime, hence appears in the sequence.
m = 5: m! - (m+1)! + (m+2)! + 1 = 4441, which is prime, hence appears in the sequence.
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Select[Table[n! - (n + 1)! + (n + 2)! + 1, {n, 200}], PrimeQ[#] &]
Select[#[[1]]-#[[2]]+#[[3]]+1&/@Partition[Range[70]!,3,1],PrimeQ] (* Harvey P. Dale, Aug 20 2021 *)
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a(n) = p=n!-(n+1)!+(n+2)!+1;if(ispseudoprime(p),return(p))
n=1;while(n<100,if(a(n),print1(a(n),", "));n++) \\ Derek Orr, Jul 27 2014
A245528
Primes of the form n! - (n + 1)! + (n + 2)! - 1.
Original entry on oeis.org
19, 101, 35999, 327599, 3306239, 81430271999, 24779106953279078399999, 10501089199335077511167999999, 1372369506422963989169318155460666934165503999999999, 117024364553755119629556890816711613171571359743999999999
Offset: 1
m = 2: m! - (m + 1)! + (m + 2)! - 1 = 19 which is prime, hence appears in the sequence.
m = 6: m! - (m + 1)! + (m + 2)! - 1 = 35999 which is prime, hence appears in the sequence.
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[a: n in [0..100] | IsPrime(a) where a is Factorial(n) - Factorial(n + 1) + Factorial(n + 2) - 1 ]; // Vincenzo Librandi, Aug 11 2014
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Select[Table[n! - (n + 1)! + (n + 2)! - 1, {n, 200}], PrimeQ[#] &]
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for(n=1,200,s=n!-(n+1)!+(n+2)!-1;if(ispseudoprime(s),print1(s,", "))) \\ Derek Orr, Aug 10 2014
Showing 1-5 of 5 results.
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