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.

A257829 The decimal representation of the average of the digits of n starts with the digits of n.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 45, 566, 1500, 2250, 3750, 18000, 383333, 4428571, 11250000, 788888888, 1000000000, 2000000000, 3000000000, 4000000000, 5000000000, 6000000000, 7000000000, 8000000000, 9000000000, 44545454545, 358333333333, 4461538461538
Offset: 1

Views

Author

Eric Angelini and Giovanni Resta, May 10 2015

Keywords

Comments

The sequence is infinite since it contains all the numbers m*10^(10^k-1), for 1 <= m <= 9 and k >= 0.

Examples

			566 is a term since the mean of its digits is (5+6+6)/3 = 17/3 and the first 3 digits of 17/3 = 5.6666... are 566. - corrected by _Joseph L. Wetherell_, Mar 17 2018
		

Crossrefs

Cf. A257830.

Programs

  • Mathematica
    (* outputs terms with at most 100 digits *) sol[nd_] := Block[{z = Range[9 nd]/nd, x}, x = FromDigits /@ First /@ RealDigits[z, 10, nd]; x[[Select[Range@ Length@x, z[[#]] == Mean@ IntegerDigits@x[[#]] &]]]]; Union@ Flatten@Array[sol, 100]