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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.
6
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
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
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 10 2024
STATUS
approved