|
%I #15 Jan 01 2021 08:07:03
%S 1,3,9,72,612,6381,34191,375201,3065211,3365919,75779001,300733722,
%T 661102209,7266033891,37610189712,631965038211,3364115985981,
%U 34975974329001,300789229729401,302881986763209,726982069546809
%N Triple and reverse digits.
%H Vaclav Kotesovec, <a href="/A163632/b163632.txt">Table of n, a(n) for n = 1..1000</a>
%H Vaclav Kotesovec, <a href="/A163632/a163632.jpg">Plot of a(n)^(1/n) for n = 1..10000</a>
%t a[n_] := a[n] = If[n==1, 1, IntegerReverse[3a[n-1]]];
%t Array[a, 40] (* _Jean-François Alcover_, Jan 01 2021 *)
%Y The following are parallel families: A000079 (2^n), A004094 (2^n reversed), A028909 (2^n sorted up), A028910 (2^n sorted down), A036447 (double and reverse), A057615 (double and sort up), A263451 (double and sort down); A000244 (3^n), A004167 (3^n reversed), A321540 (3^n sorted up), A321539 (3^n sorted down), A163632 (triple and reverse), A321542 (triple and sort up), A321541 (triple and sort down).
%Y Cf. A132064, A045539, A132078, A132114, A132113, A133361.
%K nonn,base
%O 1,2
%A _Dmitry Kamenetsky_, Aug 02 2009
%E Offset changed from 0 to 1 by _Vaclav Kotesovec_, Jan 03 2020
|
