A354782 Second digit from left in decimal expansion of 2^n (n >= 4).

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

Offset

4,1

Links

Alois P. Heinz, Table of n, a(n) for n = 4..10000

Example

2^4 = 16, so a(4) = 6. 2^5 = 32, so a(5) = 2.

Maple

a:= n-> parse(""||(2^n)[2]):
seq(a(n), n=4..112);  # Alois P. Heinz, Jul 07 2022

Mathematica

A354782[n_]:=IntegerDigits[2^n][[2]]; Array[A354782, 100, 4] (* Paolo Xausa, Oct 22 2023 *)

Prog

(Python)
def A354782(n): return int(str(1<<n)[1]) # Chai Wah Wu, Jul 07 2022

Crossrefs

Cf. A000079, A000689, A008952, A034887, A160590.

Sequence in context: A176396 A198502 A244858 * A064925 A173273 A084945

Adjacent sequences: A354779 A354780 A354781 * A354783 A354784 A354785

Keyword

nonn,base

Author

N. J. A. Sloane, Jul 07 2022, following a suggestion from Alexander Wajnberg.

Status

approved