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.

A153475 Sum of the first n even superperfect numbers (A061652).

Original entry on oeis.org

2, 6, 22, 86, 4182, 69718, 331862, 1074073686, 1152921505680920662, 309485010974266574405701718, 81129947899617655962363410845782, 85070672860182515483499614221352898646
Offset: 1

Views

Author

Omar E. Pol, Dec 27 2008

Keywords

Comments

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

Crossrefs

Cf. A092336, A019279, A061652, A153474, A153476.

Formula

a(n) = A061652(1) + A061652(2) + ... + A061652(n). - 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 1-2 of 2 results.

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

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