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 1-5 of 5 results.

A218409 Numbers k for which sigma(k)/k - 2/7 is an integer.

Original entry on oeis.org

42, 3472, 56896, 544635, 2056320, 4021920, 4357080, 6420960, 234852352, 1980840960, 19017782784, 21231974400, 60129083392, 962070839296, 47911115564928, 53603154468864, 46152495793603584, 243298521749451168, 8785228837239816192
Offset: 1

Views

Author

Zdenek Cervenka, Oct 28 2012

Keywords

Comments

a(14) > 10^11. - Donovan Johnson, Oct 31 2012
a(15) > 10^12. - Giovanni Resta, Nov 04 2012
Note that there are no terms with abundancy 9/7 or 23/7. - Michel Marcus, Jun 25 2013

Crossrefs

Cf. A218428, A218410, A218411, A218412, A218413.

Extensions

Missing term added and a(9)-a(13) from Donovan Johnson, Oct 31 2012
a(14) from Giovanni Resta, Nov 04 2012
More terms from Michel Marcus, Jun 25 2013

A218410 Numbers k for which sigma(k)/k - 3/7 is an integer.

Original entry on oeis.org

840, 55860, 1089270, 3666432, 5322240, 8714160, 10281600, 20109600, 21785400, 32104800, 9904204800, 10334134272, 4660073935104, 7322605472000, 11887123248000, 15387946358400, 78599399424000, 516876560449536, 750304684523520, 812193794048000
Offset: 1

Views

Author

Zdenek Cervenka, Oct 28 2012

Keywords

Comments

a(13) > 10^11. - Donovan Johnson, Oct 31 2012
a(13) > 10^12. - Giovanni Resta, Nov 04 2012
Note that there are no terms with abundancy 10/7 or 17/7. - Michel Marcus, Jun 25 2013

Crossrefs

Cf. A218428, A218409, A218411, A218412, A218413.

Extensions

a(5)-a(12) from Donovan Johnson, Oct 31 2012
More terms from Michel Marcus, Jun 25 2013

A218412 Numbers k for which sigma(k)/k - 5/7 is an integer.

Original entry on oeis.org

14, 588, 2520, 11466, 167580, 10999296, 67858560, 132723360, 8644446720, 31002402816, 65367751680, 10941315840000, 13980221805312, 24365070213120, 225855341712000, 317483934427296, 901703887257600, 1550629681348608, 8494794723340800
Offset: 1

Views

Author

Zdenek Cervenka, Oct 28 2012

Keywords

Comments

a(12) > 10^11. - Donovan Johnson, Oct 31 2012
a(12) > 10^12. - Giovanni Resta, Nov 04 2012

Crossrefs

Cf. A218428, A218409, A218410, A218411, A218413.

Extensions

a(6)-a(11) from Donovan Johnson, Oct 31 2012
More terms from Michel Marcus, Jun 25 2013

A218413 Numbers k for which sigma(k)/k - 6/7 is an integer.

Original entry on oeis.org

168, 11172, 217854, 228480, 446880, 220093440, 5228496000, 10805558400, 14091504577920, 583455456460800, 2583890834482298880, 5510058011880428160, 224050000769667072000, 1022756201136515973120, 1314073124731389718080, 2661277331943365990400
Offset: 1

Views

Author

Zdenek Cervenka, Oct 28 2012

Keywords

Comments

a(9) > 10^11. - Donovan Johnson, Oct 31 2012
a(9) > 10^12. - Giovanni Resta, Nov 04 2012
Note that there are no terms with abundancy 13/7. - Michel Marcus, Jun 25 2013

Crossrefs

Cf. A218428, A218409, A218410, A218411, A218412.

Extensions

a(6)-a(8) from Donovan Johnson, Oct 31 2012
More terms from Michel Marcus, Jun 25 2013

A218428 Numbers k for which sigma(k)/k - 1/7 is an integer.

Original entry on oeis.org

7, 56, 3724, 333312, 939466752, 88884432000, 95088913920, 183694492800, 85621850496000, 120354474240000, 176951824358400, 239555577824640, 268015772344320, 2056513874688000, 9918742759833600, 93442741956748800, 149180517860774400, 230762478968017920
Offset: 1

Views

Author

Zdenek Cervenka, Oct 28 2012

Keywords

Comments

a(8) > 10^11. - Donovan Johnson, Oct 31 2012
a(9) > 10^12. - Giovanni Resta, Nov 04 2012
Note that there are no terms here with abundancy 29/7. - Michel Marcus, Jun 25 2013

Crossrefs

Cf. A218409, A218410, A218411, A218412, A218413.

Extensions

a(5)-a(7) from Donovan Johnson, Oct 31 2012
a(8) from Giovanni Resta, Nov 04 2012
More terms from Michel Marcus, Jun 25 2013
Showing 1-5 of 5 results.

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

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