A336476 a(n) = gcd(A000593(n), A336475(n)).

1, 1, 2, 1, 2, 2, 2, 1, 1, 2, 2, 2, 2, 2, 12, 1, 2, 1, 2, 2, 4, 2, 2, 2, 1, 2, 4, 2, 2, 12, 2, 1, 12, 2, 4, 1, 2, 2, 4, 2, 2, 4, 2, 2, 6, 2, 2, 2, 3, 1, 12, 2, 2, 4, 4, 2, 4, 2, 2, 12, 2, 2, 2, 1, 4, 12, 2, 2, 12, 4, 2, 1, 2, 2, 2, 2, 4, 4, 2, 2, 1, 2, 2, 4, 4, 2, 12, 2, 2, 6, 28, 2, 4, 2, 20, 2, 2, 3, 6, 1, 2, 12, 2, 2, 24

Offset

1,3

Comments

All odd terms k in A001599 (Ore's Harmonic numbers) satisfy a(k) = A336475(k).

Links

Antti Karttunen, Table of n, a(n) for n = 1..16384

Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Formula

a(n) = gcd(A000593(n), A336475(n)).

a(n) = A324121(A000265(n)).

Prog

(PARI)
A000593(n) = sigma(n>>valuation(n, 2));
A336475(n) = { my(f=factor(n)); prod(i=1, #f~, if(2==f[i, 1], 1, (1+f[i, 2]) * (f[i, 1]^f[i, 2]))); };
A336476(n) = gcd(A000593(n), A336475(n));

Crossrefs

Cf. A000265, A000593, A001227, A001599, A324121, A336475.

Cf. also A324058, A336320.

Sequence in context: A336648 A082902 A123926 * A082064 A082055 A073812

Adjacent sequences: A336473 A336474 A336475 * A336477 A336478 A336479

Keyword

nonn

Author

Antti Karttunen, Jul 30 2020

Status

approved