OFFSET
0,1
EXAMPLE
The host triangle T(r,c), defined recursively, starts in row r=0 with columns 1<=c<=r as:
1;
1,3;
1,5,11;
1,13,31,55;
1,49,121,217,337;
1,241,601,1081,1681,2401;'
...
The primes in the triangle enter the sequence, sorted in natural order. - R. J. Mathar, Sep 11 2011
MATHEMATICA
a[0, 0] = 1; a[1, 0] = 1; a[n_, 1] := a[n, 1] = n; a[1, m_] := a[1, m] = 1 a[n_, m_] := a[n, m] = a[n - 1, m] + (m - 1)!*n; aa = Delete[Union[Flatten[Table[Table[If[PrimeQ[a[n, m]] == True, a[n, m], 0], {n, 1, m}], {m, 0, 20}]]], 1]
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula, Apr 05 2005
STATUS
approved