A205372 Least s(k) such that n divides s(k)-s(j) for some jA024675.

6, 6, 9, 12, 9, 12, 18, 12, 15, 26, 15, 18, 30, 18, 21, 34, 21, 30, 34, 26, 30, 26, 50, 30, 34, 30, 39, 34, 50, 34, 76, 50, 39, 60, 39, 42, 76, 42, 45, 86, 45, 60, 64, 50, 60, 50, 56, 60, 64, 56, 60, 56, 129, 60, 64, 60, 69, 64, 93, 64, 76, 134, 69, 76, 69, 72, 76

Offset: 1

Author

Clark Kimberling, Jan 26 2012

Keywords

• nonn

Comments

For a guide to related sequences, see A204892.

a(n) >= n+4, with equality if and only if n+4 is in A024675.

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A024675, A205153, A204892.

Programs

Maple

N:= 200: # for terms before the first > the greatest prime <= N
P:= select(isprime, [seq(i,i=3..N,2)]):
S:= (P[1..-2]+P[2..-1])/2:
f:= proc(n) local T,R,i;
   T:= S mod n;
   R:= {}:
   for i from 1 to nops(T)-1 do
     R:= R union {T[i]};
     if member(T[i+1],R) then return S[i+1] fi;
   od;
   FAIL
end proc:
Res:= NULL:
for n from 1 do
  v:= f(n);
  if v = FAIL then break fi;
  Res:= Res, v
od:
Res; # Robert Israel, Sep 09 2020

Mathematica

(See the program at A205153.)