A189554 Composite numbers n such that x' = n has no integer solution, where x' is the arithmetic derivative (A003415) of x.

35, 57, 65, 93, 117, 125, 145, 177, 189, 205, 207, 209, 217, 219, 237, 245, 261, 289, 303, 305, 323, 325, 345, 377, 387, 393, 413, 415, 427, 429, 453, 473, 477, 485, 497, 513, 515, 517, 529, 531, 533, 537, 553, 561, 597, 605, 625, 629, 639, 657, 665, 681

Offset: 1

Author

T. D. Noe, Apr 24 2011

Keywords

• nonn

Comments

These are the composite terms of A098700. The prime terms of A098700 are in A189483. Apparently all terms are odd.

References

• See A003415.

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A003415, A098700, A099302, A189483.

Formula

Composite k such that A099302(k) = 0.