A364720 Numbers k such that d(k) > d(k+1) > d(k+2) > d(k+3) > d(k+4), where d(n) is the number of divisors of n.

28974, 28975, 39150, 39444, 39445, 44863, 60775, 64015, 68875, 71995, 75174, 79135, 79848, 79849, 91195, 103615, 113904, 113905, 118825, 126294, 141955, 143143, 148974, 149823, 150955, 154375, 160734, 160735, 160974, 161343, 167824, 171925, 177330, 181194, 181195

Offset

1,1

Links

Seiichi Manyama, Table of n, a(n) for n = 1..1000

Mathematica

Flatten@Position[Differences@# &/@Partition[DivisorSigma[0, Range@1000000], 5, 1], {_?(# < 0 &) ..}] (* Hans Rudolf Widmer, Mar 11 2024 *)

Prog

(PARI) isok(n) = numdiv(n)>numdiv(n+1) && numdiv(n+1)>numdiv(n+2) && numdiv(n+2)>numdiv(n+3) && numdiv(n+3)>numdiv(n+4);

Crossrefs

Cf. A000005, A075029.

Cf. A074827, A364718, A364719.

Sequence in context: A252319 A237232 A031636 * A235820 A235817 A235576

Adjacent sequences: A364717 A364718 A364719 * A364721 A364722 A364723

Keyword

nonn,easy

Author

Seiichi Manyama, Aug 04 2023

Status

approved