OFFSET
1,1
COMMENTS
Row sums = the prime count, A049084: (0, 1, 2, 0, 3, 0, 4, 0, 0, 0, 5, ...).
LINKS
Muniru A Asiru, Table of n, a(n) for n = 1..1275(rows n=1..50)
FORMULA
Triangle read by rows, T(n,k) = 1 if n & k are prime, 0 otherwise.
The n-th row = n zeros if n is a nonprime; first n terms of A010051 (the characteristic function of primes) if n is prime.
EXAMPLE
First few rows of the triangle are:
0;
0, 1;
0, 1, 1;
0, 0, 0, 0;
0, 1, 1, 0, 1;
0, 0, 0, 0, 0, 0;
0, 1, 1, 0, 1, 0, 1;
...
Row 5 = first 5 terms of A010051: (0, 1, 1, 0, 1).
T(5,3) = 1 since (5,3) are prime; but T(5,4) = 0 since 4 is a nonprime.
MAPLE
T:=(n, k)->`if`(isprime(n) and isprime(k), 1, 0): seq(seq(T(n, k), k=1..n), n=1..12); # Muniru A Asiru, Oct 28 2018
MATHEMATICA
nn = 11; Flatten[Table[Table[If[And[PrimeQ[n], PrimeQ[k]], 1, 0], {k, 1, n}], {n, 1, nn}]] (* Mats Granvik, Oct 28 2018 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Aug 23 2008
STATUS
approved