A008565 Digits of powers of 4.

1, 4, 1, 6, 6, 4, 2, 5, 6, 1, 0, 2, 4, 4, 0, 9, 6, 1, 6, 3, 8, 4, 6, 5, 5, 3, 6, 2, 6, 2, 1, 4, 4, 1, 0, 4, 8, 5, 7, 6, 4, 1, 9, 4, 3, 0, 4, 1, 6, 7, 7, 7, 2, 1, 6, 6, 7, 1, 0, 8, 8, 6, 4, 2, 6, 8, 4, 3, 5, 4, 5, 6, 1, 0, 7, 3, 7, 4, 1, 8, 2, 4, 4, 2, 9, 4, 9, 6, 7, 2, 9, 6, 1, 7, 1, 7, 9, 8, 6, 9, 1, 8, 4

Offset

0,2

Comments

Irregular table with row length sequence A210434. - Jason Kimberley, Nov 26 2012

The constant whose decimal expansion is this sequence is irrational (Mahler, 1981). - Amiram Eldar, Mar 23 2025

Links

Robert Israel, Table of n, a(n) for n = 0..10008 (rows 0 to 181, flattened)

Kurt Mahler, On some irrational decimal fractions, Journal of Number Theory, Vol. 13, No. 2 (1981), pp. 268-269.

Example

Triangle begins:
  1;
  4;
  1, 6;
  6, 4;
  2, 5, 6;
  1, 0, 2, 4;
  4, 0, 9, 6;
  1, 6, 3, 8, 4;
  6, 5, 5, 3, 6;
  2, 6, 2, 1, 4, 4;
  1, 0, 4, 8, 5, 7, 6;
  ...

Maple

R:= 1: t:= 1: count:= 1:
while count < 100 do
  t:= 4*t; L:= convert(t, base, 10);
  count:= count+nops(L);
  R:= R, op(ListTools:-Reverse(L));
od:
R; # Robert Israel, May 05 2020

Mathematica

Table[IntegerDigits[4^i], {i, 0, 17}]//Flatten (* Stefano Spezia, Aug 06 2024 *)

Crossrefs

Cf. A000302 (powers of 4), A210434.

Last elements of rows give A168428.

Cf. A000455, A008564, A008566, A008567, A008568, A008569, A008570, A008571, A008572, A008573, A010054.

Sequence in context: A110312 A011242 A371498 * A205325 A021100 A021028

Adjacent sequences: A008562 A008563 A008564 * A008566 A008567 A008568

Keyword

nonn,base,easy,tabf

Author

N. J. A. Sloane

Status

approved