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".
a(n) = A066246(A014574(n)). [From Reinhard Zumkeller, Apr 06 2010]
Table of n, a(n) for n=1..52.
a(1)=1 because composite(1)-1=3=prime and composite(1)+1=5=prime.
Cf. A002808, A014574.
Sequence in context: A006553 A054273 A127567 * A005993 A028247 A209535
Adjacent sequences: A169640 A169641 A169642 * A169644 A169645 A169646
Juri-Stepan Gerasimov, Apr 04 2010
Corrected by Ray Chandler, Apr 05 2010