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

1,2

Links

Table of n, a(n) for n=1..62.

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

Crossrefs

Cf. A109411, A109826.

Sequence in context: A007536 A209887 A064801 * A327175 A193259 A008935

Adjacent sequences: A109822 A109823 A109824 * A109826 A109827 A109828

Keyword

nonn

Author

Zak Seidov, Jul 03 2005

Status

approved