A277330 a(0)=1, a(1)=2, a(2n) = A003961(a(n)), a(2n+1) = lcm(a(n),a(n+1))/gcd(a(n),a(n+1)).

1, 2, 3, 6, 5, 2, 15, 30, 7, 10, 3, 30, 35, 2, 105, 210, 11, 70, 21, 30, 5, 10, 105, 42, 77, 70, 3, 210, 385, 2, 1155, 2310, 13, 770, 231, 30, 55, 70, 105, 6, 7, 2, 21, 42, 385, 10, 165, 66, 143, 110, 231, 210, 5, 70, 1155, 66, 1001, 770, 3, 2310, 5005, 2, 15015, 30030, 17, 10010, 3003, 30, 715, 770, 105, 66, 91, 154, 231, 6, 385, 70, 15, 42, 11, 14, 3, 42, 55, 2

Offset: 0

Author

Antti Karttunen, Oct 27 2016

Keywords

• nonn

Comments

Each term is a squarefree number, A005117.

Links

• Antti Karttunen, Table of n, a(n) for n = 0..8191

Crossrefs

Cf. A001511, A003961, A005117, A007913, A019565, A048675, A055396, A260443, A264977, A277707.

Cf. A023758 (positions where coincides with A260443).

Cf. A277701, A277712, A277713 for the positions of 2's, 3's and 6's in this sequence, which are also the first three rows of array A277710.

Cf. also A255483.

Formula

a(0) = 1, a(1) = 2, a(2n) = A003961(a(n)), a(2n+1) = lcm(a(n),a(n+1))/gcd(a(n),a(n+1)).

Other identities. For all n >= 0:

a(n) = A007913(A260443(n)).

a(n) = A019565(A264977(n)), A048675(a(n)) = A264977(n).

A055396(a(n)) = A277707(A260443(n)) = A001511(n).