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

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

Author

Farideh Firoozbakht, Oct 24 2014

Keywords

• nonn

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.

Links

• Robert Price, Table of n, a(n) for n = 2..10000

Crossrefs

Cf. A000040, A182134, A246790, A246793.

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}]