A109825 Initial terms of groups in the partition of the sequence of natural numbers A109411.

1, 4, 5, 9, 10, 11, 16, 18, 21, 22, 23, 36, 39, 40, 43, 45, 47, 49, 50, 54, 60, 62, 63, 69, 70, 72, 74, 75, 89, 93, 94, 95, 96, 99, 104, 106, 107, 109, 111, 112, 115, 116, 126, 128, 135, 140, 144, 146, 147, 149, 151, 153, 159, 160, 162, 165, 170, 172, 175, 179, 184, 190

Offset: 1

Author

Zak Seidov, Jul 03 2005

Keywords

• nonn

Crossrefs

Cf. A109411, A109826.

Programs

Mathematica

s={1};a=1;Do[Do[If[Plus@@Last/@FactorInteger[(a+x)(x-a+1)/2]==2, a=x+1;AppendTo[s, a];Break[]], {x, a, 20000}], {k, 1, 100}];A109825=s