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.

A153474 Sum of first n Mersenne primes A000668.

Original entry on oeis.org

3, 10, 41, 168, 8359, 139430, 663717, 2148147364, 2305843011361841315, 618970021948533148811403426, 162259895799235311924726821691553, 170141345720365030966999228442705797280
Offset: 1

Views

Author

Omar E. Pol, Dec 27 2008

Keywords

Links

Crossrefs

Cf. A007504, A092336, A000668, A153475.

Programs

  • Mathematica
    Accumulate[2^MersennePrimeExponent[Range[15]]-1] (* Harvey P. Dale, Feb 28 2023 *)

Extensions

More terms from Max Alekseyev, Apr 13 2009

A153476 Sum of first n even superperfect numbers A061652, divided by 2.

Original entry on oeis.org

1, 3, 11, 43, 2091, 34859, 165931, 537036843, 576460752840460331, 154742505487133287202850859, 40564973949808827981181705422891, 42535336430091257741749807110676449323
Offset: 1

Views

Author

Omar E. Pol, Dec 27 2008

Keywords

Comments

Also, sum of first n superperfect numbers A019279, divided by 2, if there are no odd superperfect numbers.

Crossrefs

Cf. A153474, A153475.

Formula

a(n) = A153475(n)/2 [From Max Alekseyev, Jul 27 2009]

Extensions

More terms from Max Alekseyev, Jul 27 2009

A153487 Sum of first n perfect numbers A000396, divided by 2.

Original entry on oeis.org

3, 17, 265, 4329, 16779497, 4311714025, 73031059689, 1152921577101035753, 1329227995784915873480267885077956841, 95780971304118054976624684827067692545766545852041449
Offset: 1

Views

Author

Omar E. Pol, Dec 27 2008

Keywords

Comments

Partial sums of A133028. [From R. J. Mathar, Jan 21 2009]

Crossrefs

Cf. A000396, A092336, A153474, A153475, A153476.

Programs

  • Mathematica
    Accumulate[(# (#+1))/2&/@Select[2^Range[90]-1,PrimeQ] ]/2 (* Harvey P. Dale, Sep 04 2014 *)

Formula

a(n) = A092336(n)/2.

Extensions

More terms from R. J. Mathar, Jan 21 2009
Showing 1-3 of 3 results.

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

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