A364716 Numbers k such that d(k) < d(k+1) < d(k+2) < d(k+3), where d(n) is the number of divisors of n.

61, 193, 277, 361, 397, 421, 457, 613, 757, 997, 1213, 1237, 1453, 1657, 1867, 1873, 1933, 2137, 2347, 2593, 2797, 2917, 3013, 3183, 3217, 3361, 3427, 3481, 3517, 3697, 3721, 3805, 4057, 4083, 4177, 4261, 4603, 4621, 4717, 4771, 4813, 4957, 5029, 5041, 5101, 5107, 5223

Offset

1,1

Links

Table of n, a(n) for n=1..47.

Prog

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

Crossrefs

Cf. A000005, A075028, A364662, A364719.

Cf. A074775, A364715, A364717.

Sequence in context: A087870 A121513 A139508 * A245865 A357780 A259410

Adjacent sequences: A364713 A364714 A364715 * A364717 A364718 A364719

Keyword

nonn

Author

Seiichi Manyama, Aug 04 2023

Status

approved