OFFSET
1,1
COMMENTS
EXAMPLE
The terms (center), their binary indices (left), and their weakly decreasing prime indices (right) begin:
{2} 2 (1)
{2,3} 6 (2,1)
{1,2,3} 7 (4)
{4} 8 (1,1,1)
{2,4} 10 (3,1)
{1,2,4} 11 (5)
{1,2,3,4} 15 (3,2)
{2,5} 18 (2,2,1)
{1,2,5} 19 (8)
{1,3,5} 21 (4,2)
{4,5} 24 (2,1,1,1)
{2,4,5} 26 (6,1)
{1,2,4,5} 27 (2,2,2)
{3,4,5} 28 (4,1,1)
{1,3,4,5} 29 (10)
{6} 32 (1,1,1,1,1)
{1,6} 33 (5,2)
{2,6} 34 (7,1)
{4,6} 40 (3,1,1,1)
{1,4,6} 41 (13)
{3,4,6} 44 (5,1,1)
{1,3,4,6} 45 (3,2,2)
MATHEMATICA
Select[Range[2, 100], OddQ[IntegerLength[#, 2]+PrimePi[FactorInteger[#][[-1, 1]]]]&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 14 2024
STATUS
approved