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=1..20.
Sequence in context: A150887 A150888 A256182 * A030821 A236382 A005040
Adjacent sequences: A030974 A030975 A030976 * A030978 A030979 A030980