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.

A115890 Numbers k such that k*sigma(k) is a palindrome.

Original entry on oeis.org

1, 2, 141, 517, 1089, 1621, 1651, 2359, 17529, 20086, 124282, 1664338, 72452549, 1503846167, 14457164981, 17107594211, 17458514913, 24556027479
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Comments

a(19) > 5*10^10. - Donovan Johnson, Jul 22 2011

Examples

			1664338*sigma(1664338) = 1664338*2688588 = 4474719174744.

Crossrefs

Cf. A084122, A115891, A115892.

Extensions

a(13) from Donovan Johnson, Dec 02 2009
a(14)-a(18) from Donovan Johnson, Jul 22 2011

A115891 Numbers k such that k times phi(k) is a palindrome.

Original entry on oeis.org

1, 2, 3, 4, 17, 21, 206, 296, 309, 314, 392, 412, 444, 3016, 3074, 3182, 3552, 3632, 4944, 12998, 52009, 296448, 2306507, 2343809, 2958948, 3842106, 4419666, 14697047, 15137567, 21150749, 25829523, 29916818, 41798278, 157946358, 215882549, 318635303, 442991424
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Examples

			25829523 * phi(25829523) = 25829523 * 17219628 = 444774777477444.

Crossrefs

Cf. A084122, A115890, A115892.

Extensions

a(34)-a(37) from Donovan Johnson, Feb 17 2013
Showing 1-2 of 2 results.

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

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