Product of repunits = palindromes : another old hat?!

Zakir Seidov zakseidov at
Wed Apr 4 07:30:37 CEST 2007

Dear seqfans,

It's known that R(n)^2 (n=1..9) (square of repunits) are palindromes,
but is it old hat that
R(n)*R(m) (n=1..9) for ANY m are  also palindromes   ?!


ta12=Table[(10^k-1)/9 (10^(k+12)-1)/9,{k,9}]

Weisstein, Eric W. "Demlo Number" ,
 A002275, A002477, A080151, A080161, and A080162

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