A351091 a(n) = Product_{d|A000265(n)} A019565(A289813(d)); a product obtained from the 1-digits present in ternary expansions of the odd divisors of n.

2, 2, 6, 2, 6, 6, 4, 2, 30, 6, 10, 6, 60, 4, 90, 2, 10, 30, 4, 6, 36, 10, 6, 6, 12, 60, 210, 4, 14, 90, 84, 2, 210, 10, 84, 30, 140, 4, 18900, 6, 210, 36, 140, 10, 3150, 6, 14, 6, 168, 12, 210, 60, 14, 210, 60, 4, 36, 14, 6, 90, 4, 84, 900, 2, 900, 210, 60, 10, 90, 84, 10, 30, 4, 140, 540, 4, 60, 18900, 4, 6, 2310

Offset

1,1

Links

Table of n, a(n) for n=1..81.

Formula

a(n) = A351081(A000265(n)).

Prog

(PARI)
A019565(n) = { my(m=1, p=1); while(n>0, p = nextprime(1+p); if(n%2, m *= p); n >>= 1); (m); };
A289813(n) = { my(d=digits(n, 3)); fromdigits(vector(#d, i, if (d[i]==1, 1, 0)), 2); };
A351091(n) = { my(m=1); fordiv(n>>valuation(n, 2), d, m *= A019565(A289813(d))); (m); };

Crossrefs

Cf. A000265, A019565, A289813, A351081, A351092, A351093 (rgs-transform).

Sequence in context: A349921 A175194 A086568 * A239074 A160122 A093656

Adjacent sequences: A351088 A351089 A351090 * A351092 A351093 A351094

Keyword

nonn,easy

Author

Antti Karttunen, Jan 31 2022

Status

approved