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A339969
a(n) = gcd(n, A005940(1+n)).
4
1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 3, 1, 5, 3, 1, 1, 1, 25, 1, 9, 1, 1, 3, 1, 1, 11, 1, 7, 1, 1, 1, 1, 1, 1, 21, 1, 1, 45, 1, 1, 1, 49, 1, 1, 1, 1, 9, 1, 7, 1, 1, 1, 5, 1, 1, 1, 1, 13, 3, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 7, 3, 1, 1, 1, 1, 1, 7, 5, 1, 3, 11, 1, 15, 1, 1, 3, 1, 1, 1, 1, 1, 1, 5
OFFSET
0,7
FORMULA
a(n) = gcd(n, A005940(1+n)).
PROG
(PARI)
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
A339969(n) = gcd(n, A005940(1+n));
CROSSREFS
Cf. A005940.
Cf. also A322361, A324198, A328231.
Sequence in context: A363903 A123940 A350447 * A204120 A342666 A268032
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 25 2020
STATUS
approved