Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of 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 A278617 A194640
Adjacent sequences: A131135 A131136 A131137 * A131139 A131140 A131141
Paul Barry, Jun 17 2007