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A172253 a(n) = Successive numbers x such that value of function N(9^x-1,9^x) defined as product of different prime factors of product 9^x(9^x-1) is equal 3(9^x-1)/4 0
1, 3, 7, 9, 11, 13, 17, 19, 23, 27, 29, 31, 33, 37, 41, 43, 47, 49, 51, 53, 57, 59, 61, 67, 69, 71, 73, 77, 79, 81, 83, 87, 89, 91, 93, 97, 99 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Maximal value of radical function N(a,b,9^x) for every number 9^x and every combination of partitions a,b such that a + b = 9^x and GCD[a,b,3]=1 is never less than 3(9^x-1)/4 and is exactly equal 3(9^x-1)/4 for exponents x in this sequence. - Artur Jasinski.

Conjecture (Artur Jasinski): This sequence is infinite.

LINKS

Table of n, a(n) for n=1..37.

CROSSREFS

Sequence in context: A069254 A105585 A080903 * A104381 A136333 A134454

Adjacent sequences:  A172250 A172251 A172252 * A172254 A172255 A172256

KEYWORD

nonn

AUTHOR

Artur Jasinski, Jan 29 2010

STATUS

approved

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Last modified October 21 03:24 EDT 2019. Contains 328291 sequences. (Running on oeis4.)