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.

A319603 a(n) = n^3 + reversal of digits of n^3.

Original entry on oeis.org

0, 2, 16, 99, 110, 646, 828, 686, 727, 1656, 1001, 2662, 9999, 10109, 7216, 9108, 11000, 8107, 8217, 16445, 8008, 10890, 95249, 88288, 56655, 68276, 85147, 58374, 47864, 122731, 27072, 49583, 119491, 109890, 79697, 100699, 112320, 86258, 82717, 150714, 64046, 81907, 162135, 150104
Offset: 0

Views

Author

Seiichi Manyama, Sep 24 2018

Keywords

Crossrefs

n^b + reversal of digits of n^b: A056964 (b=1), A061226 (b=2), this sequence (b=3).
Cf. A000578, A004165, A072384 (subsequence of primes).

Programs

  • PARI
    {a(n) = n^3+fromdigits(Vecrev(digits(n^3)))}

Formula

a(n) = A000578(n) + A004165(n).

A113800 Numbers k such that k^2 plus the reverse of k^2 gives a perfect power.

Original entry on oeis.org

2, 231, 1010, 102010, 451429, 1000100, 9426681, 1000001000, 8803095102, 10002000100, 56017891104, 1000000010000, 4811618419542
Offset: 1

Views

Author

Giovanni Resta, Jan 22 2006

Keywords

Comments

Sequence is infinite since it contains all the numbers of the form (1+100^k)*10^k and (1+100^k)^2*10^k, for k >= 1. - Giovanni Resta, Sep 24 2013

Examples

			451429^2 = 203788142041 and 203788142041 + 140241887302 = 7007^3,
9426681^2 = 88862314675761 and 88862314675761 + 16757641326888 = 10277157^2.
		

Crossrefs

Programs

  • Mathematica
    ppQ[n_] := n != 1 && GCD @@ (Transpose[FactorInteger[n]][[2]]) > 1; rev[n_] := FromDigits@Reverse@IntegerDigits@n ; lst = {}; Do[If[ppQ[n^2 + rev[n^2]], AppendTo[lst, n]], {n, 10^6}]; lst

Extensions

a(8)-a(13) from Giovanni Resta, Sep 24 2013
Showing 1-2 of 2 results.