cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A246795 a(n) = A246793(A005669(n)).

Original entry on oeis.org

1, 1, 2, 3, 5, 5, 7, 8, 9, 8, 12, 10, 11, 12, 9, 12, 15, 10, 11, 15, 10, 17, 13, 16, 20, 17, 21, 19, 19, 24, 13, 23, 18, 21, 17, 26, 26, 29, 19, 23, 23, 25, 27, 27, 29, 24, 26, 25, 33, 28, 32, 32, 31, 36, 35, 37, 42, 33, 28, 35, 30, 36, 30, 34, 44, 29, 32, 34, 33, 30, 40, 38, 34, 44
Offset: 2

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Author

Farideh Firoozbakht, Oct 24 2014

Keywords

Comments

This sequence evaluates the largest m's defined in A246793 for the index of primes where largest gaps occurs.
Conjecture: For every n, a(n) is positive.
a(75) = 44 and A246794(75) = 6 hence A182134(34952141021660495 - k) = k for 5 < k < 45, where 34952141021660495 = A005669(75).

Crossrefs

A252475 Indices of record values in A246793.

Original entry on oeis.org

2, 7, 15, 21, 30, 61, 90, 177, 216, 395, 965, 1628, 2206, 2212, 3040, 10727, 10954, 29529, 62758, 94357, 196992, 314967, 608805, 1258717, 1767289, 2449005, 7939395, 9373169, 16855002, 16855004, 32881951, 41084088, 83715358, 90288095, 151449068, 315082046
Offset: 1

Views

Author

Robert Price, Dec 17 2014

Keywords

Comments

a(51) > 3.5*10^11.

Crossrefs

A246785 a(n) is the least m>0 such that A182134(n - m) = m, or zero if there is no such m.

Original entry on oeis.org

1, 1, 1, 1, 0, 2, 2, 1, 0, 2, 2, 2, 0, 3, 2, 2, 0, 3, 0, 3, 0, 3, 2, 2, 0, 0, 4, 0, 2, 2, 2, 0, 3, 0, 4, 3, 0, 4, 4, 4, 3, 0, 4, 0, 4, 2, 2, 0, 0, 4, 0, 5, 4, 4, 3, 0, 0, 5, 0, 5, 3, 2, 0, 0, 4, 4, 2, 0, 0, 0, 5
Offset: 2

Views

Author

Farideh Firoozbakht, Oct 24 2014

Keywords

Comments

Recall that A182134(k) is the number of primes p with prime(k) < p < prime(k)^(1+1/k). The record values up to n = 56000 are the positive integers up to 21 except 13 which first occurs after 14; A246790 gives indices of these record values.

Crossrefs

Programs

  • Haskell
    a246785 n = if null ms then 0 else head ms
                where ms = [m | m <- [1 .. n-1], a182134 (n - m) == m]
    -- Reinhard Zumkeller, Nov 17 2014
  • Mathematica
    h[n_]:= If[n==0, 0, (i=Prime[n]+1; j=Prime[n]^(1+1/n); Length[Select[Range[i,j], PrimeQ]])];a1[n_]:= (For[m=1, m<=n-1 && h[n-m]!= m, m++]; m); a[k_]:= If[c=a1[k]; c==k, 0, c]; Table[a[k],{k,2,90}]
Showing 1-3 of 3 results.