A239630 Factored over the Gaussian integers, the least number having n prime factors, excluding units 1, -1, i, and -i.

2, 5, 10, 30, 130, 390, 2210, 6630, 46410, 192270, 1345890, 7113990, 49797930, 291673590, 2041715130

Offset: 1

Author

T. D. Noe, Mar 31 2014

Keywords

• nonn
• more

Comments

From Amiram Eldar, Jun 27 2020: (Start)

Indices of records of A086275.

Also, numbers with a record number of unitary divisors in Gaussian integers (A332476). (End)

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. A239629 (number of distinct factors, including units).

Cf. A332476.

Programs

Mathematica

nn = 12; t = Table[0, {nn}]; n = 0; found = 0; While[found < nn, n++; f = FactorInteger[n, GaussianIntegers -> True]; cnt = Length[f]; If[MemberQ[{-1, I, -I}, f[[1, 1]]], cnt--]; If[cnt <= nn && t[[cnt]] == 0, t[[cnt]] = n; found++]]; t

Extensions

a(13)-a(15) from Amiram Eldar, Jun 27 2020