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A239630 Factored over the Gaussian integers, the least number having n prime factors, excluding units 1, -1, i, and -i. 2
2, 5, 10, 30, 130, 390, 2210, 6630, 46410, 192270, 1345890, 7113990 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..12.

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

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).

Sequence in context: A006404 A101957 A047113 * A239629 A155580 A226963

Adjacent sequences:  A239627 A239628 A239629 * A239631 A239632 A239633

KEYWORD

nonn

AUTHOR

T. D. Noe, Mar 31 2014

STATUS

approved

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Last modified September 19 23:31 EDT 2019. Contains 327207 sequences. (Running on oeis4.)