Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 4500 articles have referenced us, often saying "we would not have discovered this result without the OEIS".
Table of n, a(n) for n=0..67.
(PARI) a(n)=if(n<4, n, valuation(denominator(polylog(1-n, 1/4)/4), 3)) \\ Charles R Greathouse IV, Jul 15 2014
Sequence in context: A039729 A074065 A024811 * A189579 A194640 A189726
Adjacent sequences: A131135 A131136 A131137 * A131139 A131140 A131141
Paul Barry, Jun 17 2007