A373494 Numbers k for which A059975(k) and A003415(k) are both multiples of 3, where A059975 is fully additive with a(p) = p-1, and A003415 is the arithmetic derivative.

1, 8, 20, 27, 36, 44, 50, 64, 68, 90, 92, 110, 116, 125, 160, 162, 164, 170, 188, 189, 198, 212, 216, 225, 230, 236, 242, 252, 275, 284, 288, 290, 306, 332, 343, 351, 352, 356, 374, 400, 404, 405, 410, 414, 425, 428, 452, 468, 470, 495, 506, 512, 513, 522, 524, 530, 540, 544, 548, 575, 578, 590, 596, 605, 630, 637

Offset

1,2

Comments

A multiplicative semigroup: if m and n are in the sequence, then so is m*n.

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Prog

(PARI) isA373494 = A373493;

Crossrefs

Cf. A003415, A059975, A373492 (subsequence), A373493 (characteristic function).

Positions of multiples of 3 in A373378.

Intersection of A373385 and A327863.

Sequence in context: A164916 A207190 A110116 * A373473 A295971 A317760

Adjacent sequences: A373491 A373492 A373493 * A373495 A373496 A373497

Keyword

nonn

Author

Antti Karttunen, Jun 10 2024

Status

approved