0,4

a(n) is also the number of terms, counted with multiplicity, in a prime factorization of n + i in the ring of Gaussian integers. - Jason Kimberley, Dec 17 2011

Charles R Greathouse IV, Table of n, a(n) for n = 0..10000

A193330[n_Integer] := PrimeOmega[n^2 + 1]; A193330 /@ Range[0, 100]

PrimeOmega/@(Range[0, 90]^2+1) (* Harvey P. Dale, Apr 03 2019 *)

(PARI) a(n)=bigomega(n^2+1) \\ Charles R Greathouse IV, Jul 23, 2011

Cf. A046051, A054992, A193295.

Sequence in context: A204893 A251717 A057217 * A147810 A305302 A055181

Adjacent sequences: A193327 A193328 A193329 * A193331 A193332 A193333

nonn

Vladimir Joseph Stephan Orlovsky, Jul 22 2011

approved