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.

A103168 a(n) is the remainder when (n written backwards) is divided by n.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 9, 5, 13, 6, 13, 3, 9, 15, 2, 12, 0, 9, 18, 2, 10, 18, 26, 5, 3, 13, 23, 0, 9, 18, 27, 36, 7, 15, 4, 14, 24, 34, 0, 9, 18, 27, 36, 45, 5, 15, 25, 35, 45, 0, 9, 18, 27, 36, 6, 16, 26, 36, 46, 56, 0, 9, 18, 27, 7, 17, 27, 37, 47, 57, 67, 0, 9, 18, 8, 18, 28, 38
Offset: 1

Views

Author

Labos Elemer, Jan 28 2005

Keywords

Examples

			a(n) = 0 for palindromic numbers.
		

Crossrefs

Programs

  • Mathematica
    rd[x_]:=FromDigits[Reverse[IntegerDigits[x]]] Table[Mod[rd[n], n], {n, 1, 256}]
    Table[Mod[IntegerReverse[n],n],{n,90}] (* Harvey P. Dale, Jun 20 2025 *)
  • PARI
    a(n, base=10) = my (r=fromdigits(Vecrev(digits(n, base)), base)); r%n \\ Rémy Sigrist, Apr 05 2020
    
  • Python
    def a(n): return int(str(n)[::-1])%n
    print([a(n) for n in range(1, 84)]) # Michael S. Branicky, Dec 12 2021

Extensions

Definition corrected by N. J. A. Sloane, Jul 14 2007

A103172 Start of ten consecutive primes whose digit reversals are also prime.

Original entry on oeis.org

1193, 91528739, 302706311, 777528457, 778286917, 924408493, 1177842077, 1477271183, 1477271249, 1801280717, 1811906567, 7060718569, 9338212141, 9387802769, 9387802807, 9387802817, 9427522387, 9427522409, 9944534927
Offset: 1

Views

Author

Labos Elemer, Jan 31 2005

Keywords

Examples

			1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249 and 1259 are consecutive primes.
Their digit reversals, 3911, 1021, 3121, 7121, 3221, 9221, 1321, 7321, 9421 and 9521, are all prime.
		

Crossrefs

Extensions

Edited and extended by David Wasserman, Sep 05 2006
Corrected by Farideh Firoozbakht, Sep 23 2009

A103170 Start of eight consecutive primes whose digit reversals are also prime.

Original entry on oeis.org

727, 1193, 1201, 1213, 334759, 7904639, 7904651, 9094009, 9685771, 11875307, 12503017, 19776443, 32906869, 35414443, 37376201, 70252333, 71161309, 73694129, 77454067, 91528739, 91528777, 91528807, 93907523
Offset: 1

Views

Author

Labos Elemer, Jan 31 2005

Keywords

Examples

			1193, 1201, 1213, 1217, 1223, 1229, 1231 and 1237 are consecutive primes.
Their digit reversals, 3911, 1021, 3121, 7121, 3221, 9221, 1321 and 7321, are all prime.
		

Crossrefs

Extensions

Edited by David Wasserman, Sep 05 2006

A103171 Start of nine consecutive primes whose digit reversals are also prime.

Original entry on oeis.org

1193, 1201, 7904639, 91528739, 91528777, 120890249, 154984343, 174625597, 302706311, 302706319, 312700789, 318629783, 707262887, 756791029, 777528457, 777528461, 778286917, 778286947, 923780981, 924408493, 924408497, 958610069
Offset: 1

Views

Author

Labos Elemer, Jan 31 2005

Keywords

Comments

There are large gaps in this sequence because all terms begin with 1, 3, 7, or 9.

Examples

			1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237 and 1249 are consecutive primes.
Their digit reversals, 3911, 1021, 3121, 7121, 3221, 9221, 1321, 7321 and 9421, are all prime.
		

Crossrefs

Extensions

Edited by David Wasserman, Sep 05 2006
Showing 1-4 of 4 results.