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a(n) = A027856(n)-1 = A078884(n)-2.
Table of n, a(n) for n=1..24.
A000040(20)=71 and 71+1=72=2^3*3^2=A003586(17) and 71+2=73=A000040(21), therefore 71 is a term.
Cf. A001359, A014574, A003586.
Apart from initial terms, same as A059960.
Sequence in context: A216181 A101781 A101783 * A155990 A109556 A167675
Adjacent sequences: A078880 A078881 A078882 * A078884 A078885 A078886
Reinhard Zumkeller, Dec 11 2002