A358761 Numbers k for which bigomega(k) == 1 (mod 4).

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 32, 37, 41, 43, 47, 48, 53, 59, 61, 67, 71, 72, 73, 79, 80, 83, 89, 97, 101, 103, 107, 108, 109, 112, 113, 120, 127, 131, 137, 139, 149, 151, 157, 162, 163, 167, 168, 173, 176, 179, 180, 181, 191, 193, 197, 199, 200, 208, 211, 223, 227, 229, 233, 239, 241, 243

Offset: 1

Author

Antti Karttunen, Nov 29 2022

Keywords

• nonn

Comments

Numbers k such that number of their prime factors (when counted with multiplicity, with A001222) is of the form 4n+1: 1, 5, 9, 13, 17, ..., A016813.

Equally, numbers k for which A349905(k) == 1 (mod 4).

Examples

			48 = 2^4 * 3 has 5 prime factors in total, and 5 is a number of the form 5n+1 (in A016813), therefore 48 is included in this sequence. Or equivalently, because A349905(48) = 621 = 4*155 + 1.
		

Crossrefs

Cf. A000040 (subsequence), A001222, A003415, A003961, A010051, A010873, A016813, A349905, A358751 (characteristic function).

Setwise difference A026424 \ A358763.

Cf. also A358760, A358762.

Programs

PARI

isA358761(n) = A358751(n);

Formula

{k | A010873(A001222(k)) = 1}.