A375195 Numbers k such that A025487(k) and A025487(k+1) have an equal number of divisors.

4, 8, 15, 22, 69, 116, 122, 134, 135, 168, 208, 278, 400, 453, 538, 584, 718, 1019, 1409, 1671, 1799, 2035, 2417, 2541, 2595, 2783, 3424, 3809, 3860, 4415, 5628, 6267, 6672, 6745, 6872, 6873, 7277, 9436, 9845, 10182, 10191, 10936, 11272, 11472, 12105, 16139, 16277

Offset: 1

Author

Amiram Eldar, Aug 04 2024

Keywords

• nonn

Comments

Numbers k such that A146288(k) = A146288(k+1).

The corresponding values of A146288(k) are 4, 8, 12, 16, 48, 48, 96, 80, 80, ... .

The corresponding values of A025487(k) are 6, 24, 72, 210, 5400, ... (A375196).

Numbers k such that A146288(k) = A146288(k+1) = A146288(k+2) are 134, 6872, 6699401, 12421946, ... .

Examples

			4 is a term since A146288(4) = A146288(5) = 4.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..4390

Crossrefs

Cf. A000005, A025487, A146288, A375196.

Programs

Mathematica

With[{lps = Cases[Import["https://oeis.org/A025487/b025487.txt", "Table"], {, }][[;; , 2]]}, Position[Differences[DivisorSigma[0, lps]], 0] // Flatten]

Formula

A025487(a(n)) = A375196(n).