login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Triangle T(n,k) = 0 if k-th prime is a square mod the n-th prime, otherwise 1, for 1<=k<n.
1

%I #6 May 16 2012 03:26:28

%S 1,1,1,0,1,1,1,0,0,1,1,0,1,1,1,0,1,1,1,1,0,1,1,0,0,0,1,0,0,0,1,1,1,0,

%T 1,1,1,1,0,0,1,0,1,1,0,0,1,0,0,1,1,1,0,1,1,1,0,1,0,0,1,1,1,1,1,1,0,1,

%U 0,1,1,1,1,1,0,1,0,0,1,1,1,1,0,0,0,1,0,1,0,1,0,0,0,1,0,1,1,0,1,1,1,1,0,1,1

%N Triangle T(n,k) = 0 if k-th prime is a square mod the n-th prime, otherwise 1, for 1<=k<n.

%e 1; 1,1; 0,1,1; 1,0,0,1; ... [The third row is 0,1,1 because mod 7, 2 is a square but 3 and 5 are not]

%t t[n_, k_] := Boole[ Reduce[ Mod[Prime[k] - j^2, Prime[n]] == 0, j, Integers] === False]; Flatten[ Table[ t[n, k], {n, 2, 15}, {k, 1, n - 1}]] (* _Jean-François Alcover_, May 16 2012 *)

%Y Cf. A060039.

%K nonn,tabl,easy,nice

%O 2,1

%A _N. J. A. Sloane_, Mar 17 2001

%E More terms from Larry Reeves (larryr(AT)acm.org), Mar 20 2001