A205372 Least s(k) such that n divides s(k)-s(j) for some j<k, where s=A024675.

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

1,1

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

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.)

Crossrefs

Cf. A024675, A205153, A204892.

Sequence in context: A198115 A377900 A291545 * A301690 A365786 A365783

Adjacent sequences: A205369 A205370 A205371 * A205373 A205374 A205375

Keyword

nonn

Author

Clark Kimberling, Jan 26 2012

Status

approved