OFFSET
1,1
COMMENTS
All terms are of the form 2^i*3^j where i and j are nonnegative integers.
So corresponding to each term a(n) of the sequence there exists a unique pair
(i(n),j(n)) such that a(n)=2^i(n)*3^j(n). {n,(i(n),j(n)) for n=1, 2, ...,
24 are: {1,(2,0)},{2,(4,0)},{3,(6,0)},{4,(7,0)},{5,(8,3)},{6,(14,0)},{7,(13,1)},
{8,(19,0)},{9,(18,1)},{10,(36,6)},{11,(71,13)},{12,(110,17)},{13,(206,24)},
{14,(200,30)},{15,(679,118)},{16,(679,123)},{17,(766,136)},{18,(868,158)},
{19,(1032,160)},{20,(1207,199)},{21,(1258,171)},{22,(1257,209)},{23,(1326,199)},
& {24,(3291,531)}. So for example a(10)=2^36*3^6=50096498540544 and a(24), the largest known term of the sequence, is 2^3291*3^531.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Farideh Firoozbakht, Jul 01 2009, Jul 08 2009
STATUS
approved