A089882 Number of subsets of {1, ..., n} containing exactly one twin prime pair.

0, 0, 0, 0, 8, 16, 32, 64, 128, 256, 512, 1024, 768, 1536, 3072, 6144, 12288, 24576, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 20971520, 41943040, 83886080, 167772160

Offset: 1

Author

Reinhard Zumkeller, Nov 13 2003

Keywords

• nonn

Crossrefs

Cf. A071538, A089827, A089828, A001359, A006512.

Formula

a(n) = ceiling(A089881(n)/2)*2^(n-A089881(n)).