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 1-3 of 3 results.

A134721 Bisection of Mersenne primes A000668.

Original entry on oeis.org

3, 31, 8191, 524287, 2305843009213693951, 162259276829213363391578010288127
Offset: 1

Views

Author

Omar E. Pol, Nov 11 2007

Keywords

Examples

			a(3) = 8191 because the (2*3-1=5)th Mersenne prime is 8191.

Crossrefs

Cf. A000668, A134722.

Formula

a(n) = A000668(2*n - 1).

A138834 Bisection of even superperfect numbers A061652.

Original entry on oeis.org

2, 16, 4096, 262144, 1152921504606846976, 81129638414606681695789005144064
Offset: 1

Views

Author

Omar E. Pol, Apr 06 2008

Keywords

Comments

Also, bisection of superperfect numbers A019279, if there are no odd superperfect numbers.

Links

Crossrefs

Cf. A019279, A061652, A099057, A099058, A134721, A134722.

Formula

a(n) = A061652(2*n-1). - Jinyuan Wang, Mar 14 2020

A138835 Bisection of even superperfect numbers A061652.

Original entry on oeis.org

4, 64, 65536, 1073741824, 309485009821345068724781056, 85070591730234615865843651857942052864
Offset: 1

Views

Author

Omar E. Pol, Apr 06 2008

Keywords

Comments

Also, bisection of superperfect numbers A019279, if there are no odd superperfect numbers.
Next terms have 183, 663 and more digits and are therefore not listed. - R. J. Mathar, May 22 2008

Crossrefs

Cf. A019279, A061652, A099057, A099058, A134721, A134722, A138834.
Showing 1-3 of 3 results.

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

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