A239629 Factored over the Gaussian integers, the least positive number having n prime factors, including units -1, i, and -i.

1, 2, 5, 10, 30, 130, 390, 2730, 13260, 64090, 192270, 1345890, 7113990, 49797930, 291673590, 2041715130

Offset

1,2

Comments

Here -1, i, and -i are counted as factors. The factor 1 is counted only in a(1).

Indices of records of A239627. - Amiram Eldar, Jun 27 2020

Links

Table of n, a(n) for n=1..16.

Mathematica

nn = 12; t = Table[0, {nn}]; n = 0; found = 0; While[found < nn, n++; cnt = Length[FactorInteger[n, GaussianIntegers -> True]]; If[cnt <= nn && t[[cnt]] == 0, t[[cnt]] = n; found++]]; t

Crossrefs

Cf. A001221, A001222 (integer factorizations).

Cf. A078458, A086275 (Gaussian factorizations).

Cf. A239627 (number of Gaussian factors of n, including units).

Cf. A239628 (similar to this sequence, but count all prime factors).

Cf. A239630 (number of distinct factors, excluding units).

Sequence in context: A101957 A047113 A239630 * A155580 A226963 A018386

Adjacent sequences: A239626 A239627 A239628 * A239630 A239631 A239632

Keyword

nonn,more

Author

T. D. Noe, Mar 31 2014

Extensions

a(14)-a(16) from Amiram Eldar, Jun 27 2020

Status

approved