A359161 Numbers of the form 4u+1 with an even number of prime factors (counted with multiplicity).

1, 9, 21, 25, 33, 49, 57, 65, 69, 77, 81, 85, 93, 121, 129, 133, 141, 145, 161, 169, 177, 185, 189, 201, 205, 209, 213, 217, 221, 225, 237, 249, 253, 265, 289, 297, 301, 305, 309, 321, 329, 341, 361, 365, 377, 381, 393, 413, 417, 437, 441, 445, 453, 469, 473, 481, 485, 489, 493, 497, 501, 505, 513

Offset

1,2

Links

Table of n, a(n) for n=1..63.

Prog

(PARI) isA359161(n) = A359160(n);

Crossrefs

Intersection of A016813 and A028260.

Setwise difference A046337 \ A359163.

Setwise difference A016813 \ A359151.

Cf. A108181 (subsequence).

Cf. A359160 (characteristic function).

Sequence in context: A091113 A188159 A272600 * A327862 A108181 A368696

Adjacent sequences: A359158 A359159 A359160 * A359162 A359163 A359164

Keyword

nonn

Author

Antti Karttunen, Dec 17 2022

Status

approved