A364720 -id:A364720 - cp's OEIS frontend

A364718 Numbers k such that d(k) > d(k+1) > d(k+2), where d(n) is the number of divisors of n.

45, 80, 81, 105, 165, 224, 225, 260, 261, 272, 315, 324, 345, 357, 384, 405, 435, 440, 441, 464, 465, 476, 477, 495, 512, 555, 560, 561, 567, 585, 594, 595, 620, 624, 627, 650, 651, 675, 704, 714, 715, 795, 800, 825, 836, 837, 855, 860, 861, 884, 885, 891, 896, 915

Offset: 1

Seiichi Manyama, Aug 04 2023

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Cf. A000005, A075029, A364657.

Cf. A074827, A364719, A364720.

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

A364719 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.

Original entry on oeis.org

80, 224, 260, 440, 464, 476, 560, 594, 650, 714, 836, 860, 884, 980, 1016, 1088, 1184, 1280, 1376, 1520, 1700, 1862, 1904, 2024, 2060, 2096, 2444, 2450, 2816, 2870, 2960, 2996, 3020, 3024, 3164, 3200, 3320, 3380, 3450, 3620, 3800, 3944, 3968, 4004, 4130, 4136, 4250

Offset: 1

Seiichi Manyama, Aug 04 2023

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Cf. A000005, A050944, A075029.

Cf. A074827, A364718, A364720.

Flatten@Position[Differences@#&/@Partition[DivisorSigma[0,Range@5000],4,1], {?(#<0&)..}] (* _Hans Rudolf Widmer, Mar 11 2024 *)

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

A364717 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.

Original entry on oeis.org

11371, 11372, 35521, 38281, 45613, 48121, 50821, 50822, 52321, 52322, 54421, 54422, 59341, 59342, 71821, 79621, 86873, 87181, 117841, 125737, 127852, 130021, 130022, 132051, 132206, 133396, 151082, 153221, 173221, 180001, 184973, 186481, 195541, 195542, 196171, 196172

Offset: 1

Seiichi Manyama, Aug 04 2023

nonn

Cf. A000005, A075028, A364720.

Cf. A074775, A364715, A364716.

PARI
```
isok(n) = numdiv(n)
				
```

cp's OEIS Frontend

A364718 Numbers k such that d(k) > d(k+1) > d(k+2), where d(n) is the number of divisors of n.

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A364719 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.

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A364717 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.

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