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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.
3
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
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
KEYWORD
nonn,easy
AUTHOR
Antti Karttunen, Jan 31 2022
STATUS
approved