A272044 Numbers n such that n and n^2+1 have the same number of prime factors (including multiplicities).

2, 9, 15, 18, 22, 25, 27, 34, 35, 39, 46, 49, 51, 58, 62, 63, 65, 69, 70, 75, 85, 86, 95, 98, 105, 106, 121, 125, 132, 138, 141, 145, 147, 148, 153, 158, 159, 166, 169, 172, 174, 178, 194, 201, 202, 205, 209, 212, 214, 219, 221, 226, 254, 262, 274, 282, 285, 289, 298, 299

Offset: 1

Author

Benjamin Przybocki, Apr 18 2016

Keywords

• nonn

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001222 (bigomega), A193330.

Programs

Maple

with(numtheory): A272044:=n->`if`(bigomega(n)=bigomega(n^2+1), n, NULL): seq(A272044(n), n=1..500); # Wesley Ivan Hurt, Apr 19 2016

Mathematica

Select[Range@ 300, PrimeOmega[#^2 + 1] == PrimeOmega@ # &] (* Michael De Vlieger, Apr 19 2016 *)

PARI

is(n)=bigomega(n)==bigomega(n^2+1) \\ Charles R Greathouse IV, Apr 18 2016

Formula

Numbers n such that bigomega(n) = bigomega(n^2+1).