cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A089828 Number of subsets of {1,.., n} containing at least one twin prime pair.

Original entry on oeis.org

0, 0, 0, 0, 8, 16, 48, 96, 192, 384, 768, 1536, 4352, 8704, 17408, 34816, 69632, 139264, 339968, 679936, 1359872, 2719744, 5439488, 10878976, 21757952, 43515904, 87031808, 174063616, 348127232, 696254464, 1581252608
Offset: 1

Views

Author

Reinhard Zumkeller, Nov 12 2003

Keywords

Comments

a(n) = A000079(n)-A089827(n).

Crossrefs

Cf. A071538, A001359, A006512.

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

Original entry on oeis.org

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

Views

Author

Reinhard Zumkeller, Nov 13 2003

Keywords

Crossrefs

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

Formula

a(n) = ceiling(A089881(n)/2)*2^(n-A089881(n)).
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.