A349261 a(n) is the least number k such that A349258(k) = A349258(k+1) = n.

2, 14, 125, 135, 2079, 21735, 2730375, 916352, 5955200, 4122495, 444741759, 7391633535, 98228219264

Offset

1,1

Links

Table of n, a(n) for n=1..13.

Example

2 is a term since A349258(2) = A349258(3) = 1.
14 is a term since A349258(14) = A349258(15) = 2.

Mathematica

f[p_, e_] := 2^DigitCount[e, 2, 1] - 1; c[1] = 0; c[n_] := Plus @@ f @@@ FactorInteger[n]; seq[len_, nmax_] := Module[{s = Table[0, {len}], k = 0, n = 1, i}, While[n < nmax && k < len, i = c[n]; If[c[n + 1] == i && i <= len && s[[i]] == 0, k++; s[[i]] = n]; n++]; TakeWhile[s, # > 0 &]]; seq[8, 3*10^6]

Crossrefs

Cf. A349258.

Similar sequences: A075036, A093548, A115186, A343818.

Sequence in context: A283184 A319536 A060468 * A121082 A216595 A155650

Adjacent sequences: A349258 A349259 A349260 * A349262 A349263 A349264

Keyword

nonn,more

Author

Amiram Eldar, Nov 12 2021

Status

approved