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A072005
Smallest solution to gcd(k, reverse(k)) = 3^n.
8
1, 3, 9, 2889, 2899999989, 4899999987, 19899999972, 29898999693, 49989958299, 49999917897, 99884394999, 372797889885, 1989767716659, 2678052898989, 17902896898419, 137530987695297, 189281899170567, 368055404997498, 14048104419899757, 437893473401621955, 218264275944702783
OFFSET
0,2
LINKS
FORMULA
a(n) = A069554(3^n).
EXAMPLE
n=4: 3^4 = 81, a(4) = 2899999989 = 3*3*3*3*35802469, reverse(a(4)) = 2*3*3*3*3*61111111; gcd = 81 = 3^n.
KEYWORD
nonn,base
AUTHOR
Labos Elemer, Jun 04 2002
EXTENSIONS
a(15)-a(20) from Giovanni Resta, Oct 30 2019
STATUS
approved