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A163074 Swinging primes: primes which are within 1 of a swinging factorial (A056040). 5
2, 3, 5, 7, 19, 29, 31, 71, 139, 251, 631, 3433, 12011, 48619, 51479, 51481, 2704157, 155117519, 280816201, 4808643121, 35345263801, 81676217699, 1378465288199, 2104098963721, 5651707681619, 94684453367401, 386971244197199, 1580132580471899, 1580132580471901 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Union of A163075 and A163076.
LINKS
Peter Luschny, Swinging Primes.
EXAMPLE
3$ + 1 = 7 is prime, so 7 is in the sequence. (Here '$' denotes the swinging factorial function.)
MAPLE
# Seq with arguments <= n:
a := proc(n) select(isprime, map(x -> A056040(x)+1, [$1..n]));
select(isprime, map(x -> A056040(x)-1, [$1..n]));
sort(convert(convert(%%, set) union convert(%, set), list)) end:
MATHEMATICA
Reap[Do[f = n!/Quotient[n, 2]!^2; If[PrimeQ[p = f - 1], Sow[p]]; If[PrimeQ[p = f + 1], Sow[p]], {n, 1, 45}]][[2, 1]] // Union (* Jean-François Alcover, Jun 28 2013 *)
CROSSREFS
Sequence in context: A025019 A140327 A346167 * A230041 A068803 A184902
KEYWORD
nonn
AUTHOR
Peter Luschny, Jul 21 2009
EXTENSIONS
More terms from Jinyuan Wang, Mar 22 2020
STATUS
approved

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Last modified February 25 13:12 EST 2024. Contains 370330 sequences. (Running on oeis4.)