[seqfan] Re: d(n) = d(n-1)*d(n-2) & d(n) = d(n+1)*d(n+2)

[Maximilian Hasler]

I don't think they are on OEIS....
( I also checked for seq. n+1 and n+2 )

Maximilian

On Fri, Feb 12, 2010 at 8:48 PM, Leroy Quet <q1qq2qqq3qqqq at yahoo.com> wrote:
> Could someone calculate a few terms of these sequences, please? Are they in the EIS yet?
>
> 3) Those positive integers n such that d(n) = d(n+1)*d(n+2).
>
> 96,...

(21:18) gp > o=d=1;for(i=3,20000,if(o+0==(o=d)*d=numdiv(i),print1(i-2",")))

96,105,165,216,280,315,345,357,408,465,522,552,561,616,624,640,696,
744,760,837,861,885,920,924,945,990,1032,1056,1128,1185,1281,1302,
1368,1386,1416,1464,1560,1640,1785,1830,1860,1905,1950,2037,2142,
2184,2296,2360,2394,2432,2445,2466,2565,2610,2632,2691,2712,2850,
2877,2907,3021,3036,3045,3105,3165,3201,3213,3220,3234,3270,3336,
3456,3546,3591,3621,3640,3690,3726,3762,3801,3880,3927,3945,3990,
4077,4131,4137,4152,4230,4280,4296,4305,4326,4389,4446,4480,4485,
4641,4692,4712,4770,4776,4845,4902,4917,4935,4968,5005,5016,5145,
5160,5240,5304,5313,5320,5340,5346,5352,5385,5397,5418,5496,5505,
5640,5715,5736,5865,5896,6171,6380,6405,6420,6435,6440,6456,6504,
6520,6545,6570,6630,6657,6696,6762,6777,6786,6792,6870,6981,7011,
7032,7040,7077,7112,7125,7185,7464,7480,7515,7521,7540,7548,7557,
7590,7592,7641,7672,7686,7701,7866,7875,7896,7905,7917,8040,8088,
8120,8265,8310,8330,8376,8385,8421,8456,8536,8625,8697,8730,8840,
8850,8856,8946,8961,9030,9045,9096,9165,9192,9207,9234,9256,9288,9345,
9440,9450,9465,9480,9504,9555,9625,9672,9741,9747,9752,9810,9856,9885,
9933,9960,9990,10017,10040,10065,10152,10170,10230,10341,10392,10455,
10458,10461,10476,10488,10545,10731,10797,10850,10857,10935,10965,
11000,11001,11046,11060,11115,11136,11220,11286,11305,11336,11382,
11424,11445,11480,11481,11502,11544,11697,11704,11718,11720,11736,
11805,11850,11865,11895,11928,11960,11985,12040,12056,12075,12177,
12195,12250,12261,12264,12267,12345,12360,12408,12441,12450,12597,
12650,12762,12896,13000,13080,13101,13160,13161,13240,13266,13335,
13377,13400,13410,13482,13485,13512,13626,13640,13650,13656,13685,
13905,13940,13944,13952,13995,14025,14040,14105,14130,14148,14205,
14241,14310,14445,14532,14536,14637,14664,14712,14760,14796,14865,
14877,14982,15045,15080,15081,15093,15176,15285,15510,15512,15582,
15648,15675,15720,15744,15765,15786,15795,15801,15816,15880,15972,
16002,16005,16008,16050,16086,16125,16170,16215,16230,16290,16296,
16422,16445,16506,16520,16545,16680,16728,16821,16856,16902,16968,
17082,17085,17112,17145,17157,17205,17304,17320,17336,17416,17493,
17595,17625,17655,17724,17766,17802,17836,17928,18040,18057,18075,
18120,18130,18285,18340,18411,18441,18456,18560,18592,18645,18648,
18912,18921,18924,18957,18981,18984,19032,19050,19065,19176,19352,
19422,19437,19572,19581,19608,19734,19737,19896,19912,19971,

  ***   last result computed in 94 ms.