A275240
Highly composite numbers of class 2 (see comment in A275239).
Original entry on oeis.org
5, 9, 10, 20, 40, 80, 84, 192, 210, 288, 432, 480, 1200, 1320, 1800, 2640, 3600, 3780, 6480, 7200, 8400, 10920, 13860, 21840, 31680, 32760, 69300, 73920, 75600, 100800, 120120, 138600, 226800, 240240, 302400, 388080, 393120, 771120, 776160, 942480, 1310400
Offset: 1
A275241
Highly composite numbers of class 3 (see comment in A275239).
Original entry on oeis.org
7, 14, 28, 42, 90, 216, 300, 504, 1296, 1344, 1512, 1980, 3024, 3960, 8640, 9360, 11880, 15840, 22680, 33600, 35280, 36960, 70560, 85680, 120960, 151200, 249480, 342720, 415800, 856800, 960960, 982800, 1552320, 1572480, 1884960, 3243240, 3880800, 3931200
Offset: 1
A275242
Highly composite numbers of class 4 (see comment in A275239).
Original entry on oeis.org
11, 15, 32, 54, 96, 264, 396, 528, 540, 1560, 2016, 3120, 4032, 4200, 8820, 10560, 10800, 13440, 16380, 23760, 37440, 37800, 71280, 79200, 87360, 90720, 128520, 163800, 257040, 352800, 369600, 428400, 443520, 861840, 887040, 997920, 1580040, 1940400, 1965600
Offset: 1
A275243
Highly composite numbers of class 5 (see comment in A275239).
Original entry on oeis.org
13, 21, 44, 56, 100, 108, 270, 450, 560, 576, 600, 1584, 1848, 2100, 3240, 4320, 9072, 9900, 11088, 14040, 16800, 28080, 39600, 40320, 80640, 92400, 141120, 143640, 171360, 287280, 383040, 453600, 471240, 900900, 1028160, 1053360, 1670760, 1995840, 2106720
Offset: 1
A275244
Highly composite numbers of class 6 (see comment in A275239).
Original entry on oeis.org
17, 22, 45, 64, 66, 112, 126, 280, 468, 624, 630, 1620, 1890, 2340, 3696, 4620, 11340, 14280, 17640, 28560, 41580, 81900, 95040, 95760, 147840, 176400, 180180, 294840, 403200, 411840, 458640, 480480, 907200, 917280, 1113840, 1713600, 1867320, 2217600, 3825360
Offset: 1
A335029
Numbers that are not practical (A237287) and have more divisors than any smaller number that is not practical.
Original entry on oeis.org
3, 9, 10, 44, 70, 225, 315, 770, 1575, 2835, 3465, 10010, 17325, 31185, 45045, 121275, 135135, 225225, 405405, 675675, 1576575, 2027025, 2297295, 3828825, 6891885, 11486475, 26801775, 34459425, 43648605, 72747675, 130945815, 218243025, 509233725, 654729075, 1003917915
Offset: 1
The first 5 numbers that are not practical are 3, 5, 7, 9, 10. Their numbers of divisors are 2, 2, 2, 3, 4. The record numbers of divisors are 2, 3 and 4 which occur at 3, 9 and 10.
-
f[p_, e_] := (p^(e + 1) - 1)/(p - 1); pracQ[fct_] := (ind = Position[fct[[;; , 1]]/(1 + FoldList[Times, 1, f @@@ Most@fct]), _?(# > 1 &)]) == {}; seq = {}; dm = 1; Do[fct = FactorInteger[n]; d = Times @@ (1 + Last/@ fct); If[d > dm && !pracQ[fct], dm = d; AppendTo[seq, n]], {n, 3, 10^5}]; seq
Showing 1-6 of 6 results.
Comments