A080112 - OEIS

%I #12 Sep 20 2022 08:38:36

%S 2,3,4,5,6,9,11,12,15,17,20,22,23,27,32,36,39,43,46,52,54,56,58,64,72,

%T 76,81,83,85,92,96,103,109,111,118,120,128,132,133,146,150,154,156,

%U 157,164,166,167,173,175,179,182,185,190,200,202,207,215,222,225,228,229

%N Positions of A080114 in A000040.

%p A080112 := proc(n) option remember; local i; if(1 = n) then RETURN(2); fi; i := A080112(n-1)+1; while(i > 0) do if(A080110(i) > 0) then RETURN(i); fi; i := i+1; od; end;

%t s[p_, u_] := Sum[JacobiSymbol[j, p], {j, 1, u}]; Select[Range[2, 300], (p = Prime[#]; AllTrue[Range[(p - 1)/2], s[p, #] >= 0 &]) &] (* _Jean-François Alcover_, Mar 07 2016 *)

%o (Sage)

%o @CachedFunction

%o def A080112(n) :

%o      if 1 == n : return 2

%o      i = A080112(n-1) + 1

%o      while i > 0 :

%o          if A080110(i) > 0 : return i

%o          i += 1

%o [A080112(n) for n in (1..61)] # _Peter Luschny_, Aug 09 2012

%Y Complement of A080113. Characteristic function: A080110.

%K nonn

%O 1,1

%A _Antti Karttunen_, Feb 11 2003