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 1-3 of 3 results.

A104692 Numbers n such that in n^3, number of odd digits is less than number of even digits.

Original entry on oeis.org

2, 4, 6, 10, 14, 16, 20, 22, 24, 29, 30, 32, 35, 36, 38, 40, 41, 42, 44, 50, 52, 60, 61, 62, 63, 64, 65, 66, 70, 74, 80, 86, 88, 90, 92, 94, 96, 100, 102, 104, 107, 112, 113, 114, 116, 118, 120, 122, 123, 124, 126, 127, 129, 130, 131, 132, 134, 135
Offset: 1

Views

Author

Zak Seidov, Mar 18 2005

Keywords

Comments

Numbers n such that in n^3, number of odd digits equals the number of even digits A104641. Numbers n such that in n^3, number of odd digits is larger than number of even digits A104693; rearrangement of positive integers according to number of odd and even digits in n^3 A104694, A104695; number of even digits in n^3 A104639, number of odd digits in n^3 A104640.

Crossrefs

Programs

  • Mathematica
    EvedQ[n_]:= Module[{idn3 = IntegerDigits[n^3]}, Count[idn3, ?OddQ] < Count[idn3, ?EvenQ]]; Select[Range[2000], EvedQ] (* G. C. Greubel, Aug 14 2018 *)
  • PARI
    isok(n) = my(d = digits(n^3)); sum(i=1, #d, d[i] % 2) < sum(i=1, #d, 1 - (d[i] % 2)); \\ Michel Marcus, Oct 05 2013

Extensions

More terms from Michel Marcus, Oct 05 2013

A104694 Rearrangement of positive integers according to number of odd and even digits in n^3.

Original entry on oeis.org

2, 3, 1, 4, 12, 5, 6, 18, 7, 10, 19, 8, 14, 21, 9, 16, 47, 11, 20, 53, 13, 22, 54, 15, 24, 67, 17, 29, 68, 23, 30, 69, 25, 32, 72, 26, 35, 75, 27, 36, 76, 28, 38, 78, 31, 40, 84, 33, 41, 85, 34, 42, 87, 37, 44, 89, 39, 50, 93, 43
Offset: 1

Views

Author

Zak Seidov, Mar 18 2005

Keywords

Crossrefs

Formula

{A104692(n), A104691(n), A104693(n)}, n=1, 2, ...

A104695 Rearrangement of positive integers inverse to A104694.

Original entry on oeis.org

3, 1, 2, 4, 6, 7, 9, 12, 15, 10, 18, 5, 21, 13, 24, 16, 27, 8, 11, 19, 14, 22, 30, 25, 33, 36, 39, 42, 28, 31, 45, 34, 48, 51, 37, 40, 54, 43, 57, 46, 49, 52, 60, 55
Offset: 1

Views

Author

Zak Seidov, Mar 18 2005

Keywords

Crossrefs

Formula

a(n) shows the position of n in A104694.
Showing 1-3 of 3 results.