A330745 Primorial deflation of A019505(n), where A019505(n) is smallest number with same number of divisors as 2*A019505(n-1), starting from A019505(1) = 1.

1, 2, 4, 3, 6, 12, 24, 10, 20, 40, 30, 60, 21, 42, 84, 168, 336, 66, 132, 264, 528, 396, 792, 117, 234, 468, 936, 1872, 780, 1560, 612, 1224, 2448, 1020, 2040, 684, 1368, 2736, 1140, 2280, 4560, 1596, 3192, 1380, 2760, 5520, 1932, 3864, 7728, 15456, 11592, 23184, 1827, 3654, 7308, 14616, 29232, 1953, 3906, 7812, 15624, 31248, 62496

Offset

1,2

Comments

a(n) is the unique integer k such that A108951(k) = A019505(n).

Conjectured to be a subsequence of A329902.

Terms computed from b-file of A019505 provided by R. J. Mathar.

Links

Table of n, a(n) for n=1..63.

Formula

a(n) = A329900(A019505(n)).

Prog

(PARI) A330745(n) = A329900(A019505(n));

Crossrefs

Cf. A019505, A108951, A329900, A329902.

Cf. A330744 (conjectured subsequence).

Sequence in context: A329902 A366028 A091274 * A122525 A054589 A051851

Adjacent sequences: A330742 A330743 A330744 * A330746 A330747 A330748

Keyword

nonn

Author

Antti Karttunen, Jan 10 2020

Status

approved