A346481 - OEIS

A346481

a(n) = A346467(n) / A346466(n) = lcm S / lcm {d in S, d+1 | n}, with S = {d | n-1, d+1 is prime}.

1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 8, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 8, 1, 5, 1, 1, 1, 18, 1, 14, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 40, 1, 1, 1, 21, 1, 1, 1, 1, 1, 15, 1, 46, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 13

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OFFSET

1,9

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..20000

FORMULA

a(n) = A346467(n) / A346466(n).

PROG

(PARI) A346481(n) = if(1==n, n, my(m1=1, m2=1); fordiv(n-1, d, if(isprime(1+d), m1 = lcm(m1, d); if(!(n%(1+d)), m2 = lcm(m2, d)))); (m1/m2));

CROSSREFS

Cf. A346466, A346467.

Sequence in context: A329314 A092931 A147300 * A240228 A110503 A030556

Adjacent sequences: A346478 A346479 A346480 * A346482 A346483 A346484

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jul 31 2021

STATUS

approved