%I A033618
%S A033618 2,2,2,2,3,2,2,3,2,3,3,2,4,5,2,3,3,4,3,4,3,4,5,3,3,3,3,2,3,3,3,6,3,2,3,
%T A033618 2,3,3,3,3,4,2,3,3,7,3,4,3,4,5,4,3,4,2,2,3,3,3,4,3,3,3,3,4,3,2,3,6,2,3,
               3
%N A033618 Number of ways n-th repdigit number (A010785[ n ]) can be expressed as 
               a polygonal number.
%H A033618 M. Keith, <a href="http://www.cs.uwaterloo.ca/journals/JIS/index.html">
               On Repdigit Polygonal Numbers</a>, J. Integer Sequences, Vol. 1, 
               1998, #6.
%e A033618 The n-th k-sided polygonal number is P(n,k)=n((k-2)n+4-k)/2 (k >= 2, 
               n >= 1). For each repdigit number R>=2, sequence gives number of 
               (n,k) such that P(n,k)=R.
%Y A033618 Sequence in context: A074592 A089993 A047931 this_sequence A061357 A138139 
               A127992
%Y A033618 Adjacent sequences: A033615 A033616 A033617 this_sequence A033619 A033620 
               A033621
%K A033618 nonn
%O A033618 2,1
%A A033618 Mike Keith (domnei(AT)aol.com)