A373488 Nonprime natural numbers k such that A276085(k) is a multiple of A003415(k), where A003415 is the arithmetic derivative and A276085 is the primorial base log-function.

1, 10, 15, 28, 35, 91, 143, 155, 161, 187, 203, 209, 215, 221, 295, 299, 319, 323, 329, 341, 371, 377, 391, 403, 437, 515, 538, 559, 581, 611, 649, 667, 689, 703, 707, 731, 779, 803, 851, 869, 893, 899, 901, 923, 979, 989, 1037, 1073, 1081, 1121, 1139, 1147, 1189, 1199, 1207, 1219, 1261, 1363, 1391, 1403, 1457, 1498

Offset

1,2

Comments

Nonsquarefree terms are rare: only 3 less than 2^20: 28, 33212, 855523.

Links

Antti Karttunen, Table of n, a(n) for n = 1..25127

Prog

(PARI) isA373488(n) = (!isprime(n) && A373486(n));

Crossrefs

Setwise difference A373487 \ A000040.

Cf. A003415, A276085, A369650, A373486.

Sequence in context: A051990 A246447 A254362 * A182427 A171956 A271743

Adjacent sequences: A373485 A373486 A373487 * A373489 A373490 A373491

Keyword

nonn

Author

Antti Karttunen, Jun 09 2024

Status

approved