A308749 Smallest positive m such that n*m is a partial sum of primes.

2, 1, 43, 7, 1, 1145, 4, 20, 71, 1, 7, 1879, 376, 2, 458, 10, 1, 1763, 46, 5, 147, 20, 38, 983, 4, 188, 43, 1, 2, 229, 94, 5, 397, 7, 2531, 988, 40, 23, 912, 4, 1, 6692, 3, 10, 3769, 19, 62, 741, 63, 2, 1716, 94, 20, 1783, 8, 589, 191, 1, 27, 430, 986, 47, 49

Offset

1,1

Links

Alois P. Heinz, Table of n, a(n) for n = 1..20000

Formula

a(n) = A007504(A053050(n))/n.

a(n) = 1 <=> n in { A007504 } \ { 0 }.

Maple

s:= proc(n) option remember; `if`(n=0, 0, ithprime(n)+s(n-1)) end:
a:= proc(n) option remember; local k; for k
      while irem(s(k), n)>0 do od; s(k)/n
    end:
seq(a(n), n=1..70);

Mathematica

s[n_] := s[n] = If[n == 0, 0, Prime[n] + s[n-1]];
a[n_] := a[n] = Module[{k}, For[k = 1, True, k++, If[Mod[s[k], n] <= 0, Return[s[k]/n]]]];
Table[a[n], {n, 1, 70}] (* Jean-François Alcover, Dec 08 2023, after Alois P. Heinz *)

Crossrefs

Cf. A000040, A007504, A053050.

Sequence in context: A228860 A271204 A275706 * A260884 A214221 A100018

Adjacent sequences: A308746 A308747 A308748 * A308750 A308751 A308752

Keyword

nonn

Author

Alois P. Heinz, Jun 21 2019

Status

approved