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.

A095198 a(1) = 1, a(n+1) = prime(n)*Digit reversal of a(n).

Original entry on oeis.org

1, 2, 6, 30, 21, 132, 3003, 51051, 285285, 13399386, 1983580599, 308476470621, 4664762967711, 48285399661224, 1815318072406212, 99924007282353507, 3738372398312278947, 442424606197031564007, 42728372978287991878884
Offset: 1

Views

Author

Amarnath Murthy, Jun 05 2004

Keywords

Crossrefs

Cf. A095197.

Programs

  • Mathematica
    Transpose[NestList[{First[#]+1,Prime[First[#]]FromDigits[Reverse[ IntegerDigits[Last[#]]]]}&,{1,1},25]][[2]] (* Harvey P. Dale, Mar 02 2012 *)

Extensions

Corrected and extended by Rick L. Shepherd, Jun 07 2004

A333302 Numbers produced by iteratively sorting the digits of the last number from largest to smallest in base 10 and then doubling, starting with the number 1.

Original entry on oeis.org

1, 2, 4, 8, 16, 122, 442, 884, 1768, 17522, 150442, 1088420, 17684200, 175284200, 1750844200, 17508842000, 177508420000, 1755084200000, 17510842000000, 175084220000000, 1750844200000000, 17508842000000000, 177508420000000000, 1755084200000000000
Offset: 1

Views

Author

Ethan Hulinsky, Mar 14 2020

Keywords

Comments

It appears that the first 8 digits begin to cycle in a period of 6 while adding one zero every iteration.

Crossrefs

Programs

  • Mathematica
    a[1] = 1; a[n_] := a[n] = 2 FromDigits@ Reverse@ Sort@ IntegerDigits@ a[n-1]; Array[a, 24] (* Giovanni Resta, Apr 15 2020 *)
  • PARI
    lista(nn) = {my(a=1); print1(a, ", "); for (n=2, nn, a = 2*fromdigits(vecsort(digits(a),,4)); print1(a, ", "););} \\ Michel Marcus, Apr 16 2020
Showing 1-2 of 2 results.