login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A127859
a(n) = r(A127858(n)), where r if the cyclic replacement map of the digits d of n in base 12 defined by d->d+1 if d<11 and d->0 if d=11.
6
7, 79, 943, 11311, 135727, 1628719, 19544623, 234535471, 2814425647, 33773107759, 405277293103, 4863327517231, 58359930206767, 700319162481199, 8403829949774383, 100845959397292591, 1210151512767511087
OFFSET
1,1
COMMENTS
In base 12 the sequence is 7, 67, 667, 6667, 66667, 666667, 6666667, 66666667, 666666667, 6666666667.
FORMULA
a(n) = 6*(12^n - 1)/11 + 1. - Max Alekseyev, Jul 27 2023
EXAMPLE
a(2)=66 since, in base 12, 66=56, r(56)=67 and r(56^2)=r(2630)=3741=67^2.
In base 12, a(2)=r(A127858(2))=r(56)=67. In base 10, 67 is 79.
KEYWORD
nonn,base
AUTHOR
Walter Kehowski, Feb 04 2007
EXTENSIONS
More terms from Max Alekseyev, Jul 27 2023
STATUS
approved