

A033618


Number of ways nth repdigit number, A010785(n), can be expressed as a polygonal number.


0



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, 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
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OFFSET

2,1


LINKS

Table of n, a(n) for n=2..72.
M. Keith, On Repdigit Polygonal Numbers, J. Integer Sequences, Vol. 1, 1998, #6.


EXAMPLE

The nth ksided polygonal number is P(n,k)=n((k2)n+4k)/2 (k >= 2, n >= 1). For each repdigit number R>=2, sequence gives number of (n,k) such that P(n,k)=R.


CROSSREFS

Sequence in context: A234092 A047931 A258571 * A061357 A270966 A138139
Adjacent sequences: A033615 A033616 A033617 * A033619 A033620 A033621


KEYWORD

nonn,base


AUTHOR

Mike Keith (domnei(AT)aol.com)


STATUS

approved



