login
A308749
Smallest positive m such that n*m is a partial sum of primes.
2
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
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
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jun 21 2019
STATUS
approved