A351082 a(n) = Product_{d|n} A019565(A289814(d)); a product obtained from the 2-digits present in ternary expansions of the divisors of n.

1, 2, 1, 2, 2, 6, 3, 12, 1, 4, 2, 6, 1, 12, 6, 36, 6, 30, 5, 40, 15, 20, 10, 540, 30, 60, 1, 12, 2, 36, 1, 72, 6, 36, 36, 30, 1, 20, 1, 240, 2, 540, 3, 120, 30, 100, 10, 8100, 15, 600, 90, 900, 30, 210, 28, 1008, 35, 28, 14, 7560, 21, 84, 105, 504, 28, 1260, 7, 504, 210, 3024, 42, 94500, 35, 140, 3150, 700, 420, 18900

Offset

1,2

Links

Table of n, a(n) for n=1..78.

Formula

a(n) = A019565(A289814(n)) * A293222(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); };
A289814(n) = { my(d=digits(n, 3)); fromdigits(vector(#d, i, if (d[i]==2, 1, 0)), 2); };
A351082(n) = { my(m=1); fordiv(n, d, m *= A019565(A289814(d))); (m); };

Crossrefs

Cf. A019565, A289814, A293221, A351081, A351092.

Sequence in context: A200745 A067541 A054706 * A334500 A081727 A000020

Adjacent sequences: A351079 A351080 A351081 * A351083 A351084 A351085

Keyword

nonn,easy

Author

Antti Karttunen, Jan 31 2022

Status

approved