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 1-4 of 4 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

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

A153478 Sum of first n isolated (or single) primes A007510.

Original entry on oeis.org

2, 25, 62, 109, 162, 229, 308, 391, 480, 577, 690, 817, 948, 1105, 1268, 1435, 1608, 1819, 2042, 2275, 2526, 2783, 3046, 3323, 3616, 3923, 4240, 4571, 4908, 5261, 5620, 5987, 6360, 6739, 7122, 7511, 7908, 8309, 8718, 9157, 9600
Offset: 1

Views

Author

Omar E. Pol, Dec 27 2008

Keywords

Links

Crossrefs

Cf. A000040, A007504, A007510, A048598, A071148, A153474.

Programs

  • Mathematica
    Accumulate[Select[Prime[Range[100]],!PrimeQ[#-2]&&!PrimeQ[#+2]&]]  (* Harvey P. Dale, Feb 08 2011 *)

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 1-4 of 4 results.

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

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