A293781 First differences of A293780.
3, 4, 8, 16, 16, 6, 18, 24, 12, 36, 18, 30, 24, 72, 36, 60, 48, 54, 90, 72, 120, 96, 108, 180, 144, 162, 78, 192, 216, 360, 288, 288, 120, 240, 360, 150, 90, 210, 270, 180, 300, 60, 540, 360, 240, 480, 270, 450, 90, 210, 180, 420, 540, 360, 600, 120, 1080, 450, 270
Offset: 1
Keywords
Examples
a(1) = A293780(2) - A293780(1) = 4 - 1 = 3.
Links
- Rémy Sigrist, Table of n, a(n) for n = 1..2260
- Rémy Sigrist, Colored logarithmic scatterplot of the first 2260 terms (where the color is function of the number of distinct prime factors of A293780(n))
- Rémy Sigrist, Colored logarithmic scatterplot of the first 20000 terms (provided that A293780 is a subsequence of A055932)
Programs
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Mathematica
Block[{s = {1}~Join~Array[Times @@ FactorInteger[#][[All, 1]] &, 10^4, 2], t}, t = 1 + Array[Count[Take[s, # - 1], s[[#]]] &, Length@ s]; Differences@ Map[FirstPosition[t, #][[1]] &, Union@ FoldList[Max, t]]] (* Michael De Vlieger, Oct 30 2017 *) -
PARI
lista(nn) = {nbm = 0; lastn = 0; v = vector(nn, k, factor(k)[, 1]); for (n=1, nn, vn = vector(n, k, v[k]); nbn = #select(x->(x==v[n]), vn); if (nbn > nbm, if (nbm, print1(n-lastn, ", ")); nbm = nbn; lastn = n;););} \\ Michel Marcus, Oct 31 2017