A364271 Initial digit of n^((n + 1)^(n + 2)).

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

Offset

0,3

Links

Table of n, a(n) for n=0..86.

Kevin Ryde, C code using MPFR

Formula

a(n) = floor(t / 10^floor(log_10(t))) where t = n^((n + 1)^(n + 2)).

a(n) = A000030(A030198(n)).

Example

a(2) = 2, since 2^((2 + 1)^(2 + 2)) = 2417851639229258349412352.

Mathematica

Join[{0}, Table[Floor[n^((n+1)^(n+2))/10^Floor[Log10[n^((n+1)^(n+2))]]], {n, 86}]]

Prog

(C) /* See links */

Crossrefs

Cf. A000030, A030198, A365689 (final digit).

Sequence in context: A232435 A114858 A193491 * A352062 A263340 A114583

Adjacent sequences: A364268 A364269 A364270 * A364272 A364273 A364274

Keyword

nonn,base

Author

Marco Ripà, Oct 20 2023

Extensions

More terms from Kevin Ryde, Oct 27 2023

Status

approved