A165742 First differences of A003591.

1, 2, 3, 1, 6, 2, 12, 4, 17, 7, 8, 34, 14, 16, 68, 28, 32, 87, 49, 56, 64, 174, 98, 112, 128, 348, 196, 224, 256, 353, 343, 392, 448, 512, 706, 686, 784, 896, 1024, 1412, 1372, 1568, 1792, 2048, 423, 2401, 2744, 3136, 3584, 4096, 846, 4802, 5488, 6272, 7168, 8192, 1692, 9604, 10976, 12544, 14336, 2961, 13423, 3384, 19208

Offset

1,2

Comments

Conjecturally, the limit infimum is infinite. [Charles R Greathouse IV, Jun 28 2011]

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Example

For n = 5, the 5th number of the form 2^i*7^j with i, j >= 0 is 8, and the 6th number of the form 2^i*7^j with i, j >= 0 is 14, so the difference is 14 - 8 = 6.

Prog

(PARI) diff(v)=vector(#v-1, i, v[i+1]-v[i])
list(lim)=my(v=List(), N); for(n=0, log(lim)\log(7), N=7^n; while(N<=lim, listput(v, N); N<<=1)); diff(vecsort(Vec(v))) \\ Charles R Greathouse IV, Jun 28 2011

Crossrefs

Sequence in context: A156344 A218796 A119440 * A162984 A166295 A016730

Adjacent sequences: A165739 A165740 A165741 * A165743 A165744 A165745

Keyword

nonn

Author

Mick Purcell (mickpurcell(AT)gmail.com), Sep 25 2009

Status

approved