A319991 a(n) = Product_{d|n, d<n} A019565(d)^[1 == d mod 3].

1, 2, 2, 2, 2, 2, 2, 10, 2, 2, 2, 10, 2, 60, 2, 10, 2, 2, 2, 210, 60, 2, 2, 10, 2, 140, 2, 300, 2, 42, 2, 110, 2, 2, 60, 10, 2, 132, 140, 210, 2, 60, 2, 1650, 2, 2, 2, 110, 60, 6468, 2, 700, 2, 2, 2, 115500, 132, 2, 2, 210, 2, 4620, 60, 110, 140, 330, 2, 390, 2, 1260, 2, 10, 2, 260, 308, 660, 60, 140, 2, 210210, 2, 2, 2, 115500, 2, 1092, 2

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..8192

Formula

a(n) = Product_{d|n, d<n} A019565(d)^[1 == d mod 3].

a(n) = A293214(n) / (A319990(n)*A319992(n)).

For all n >= 1:

A007814(a(n)) = A320001(n).

A048675(a(n)) = A293897(n).

A195017(a(n)) = A293895(n) mod 3.

Prog

(PARI)
A019565(n) = {my(j, v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ This function from M. F. Hasler
A319991(n) = { my(m=1); fordiv(n, d, if((d<n)&&(1==(d%3)), m *= A019565(d))); m; };

Crossrefs

Cf. A019565, A293214, A293895, A293897, A319990, A319992, A320001, A320011 (rgs-transform).

Cf. also A293221.

Sequence in context: A202448 A339165 A129381 * A323275 A139514 A330955

Adjacent sequences: A319988 A319989 A319990 * A319992 A319993 A319994

Keyword

nonn

Author

Antti Karttunen, Oct 03 2018

Status

approved