A344312 Number k such that k and k+1 have the same number of exponential divisors (A049419).

1, 2, 5, 6, 8, 10, 13, 14, 21, 22, 24, 27, 29, 30, 33, 34, 37, 38, 41, 42, 44, 46, 49, 57, 58, 61, 65, 66, 69, 70, 73, 75, 77, 78, 80, 82, 85, 86, 93, 94, 98, 101, 102, 105, 106, 109, 110, 113, 114, 116, 118, 120, 122, 124, 125, 129, 130, 133, 135, 137, 138, 141

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

1 is a term since A049419(1) = A049419(2) = 1.
8 is a term since A049419(8) = A049419(9) = 2.

Mathematica

f[p_, e_] := DivisorSigma[0, e]; ed[n_] := Times @@ f @@@ FactorInteger[n]; Select[Range[200], ed[#] == ed[# + 1] &]

Crossrefs

Cf. A049419.

Similar sequences: A005237, A006049, A343819, A344313, A344314.

Sequence in context: A363676 A047441 A284777 * A081083 A288635 A308595

Adjacent sequences: A344309 A344310 A344311 * A344313 A344314 A344315

Keyword

nonn

Author

Amiram Eldar, May 14 2021

Status

approved