OFFSET
1,2
COMMENTS
With offset 0, ((cube root of 10) to the power n) rounded up.
From Carmine Suriano, Mar 14 2020: (Start)
The terms corresponding to n = (20,21); (38,39); (41,42); (56,57); (59,60); (77,78); (80,81) ... are such that the square of first term starts with the digits of second term, and the square of second term starts with the digits of the first. For example, a(38)^2 = 2154434690032^2 = 4641588833613.... and a(39)^2 = 4641588833613^2 = 2154434690032...
(End)
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..200
EXAMPLE
a(5) = 22, 22^3 = 10648 has 5 digits, while 21^3 = 9261 has 4 digits.
MATHEMATICA
Table[Ceiling[10^(n/3)], {n, 0, 40}] (* Vincenzo Librandi, Jan 09 2014 *)
PROG
(Magma) [Ceiling(10^(n/3)): n in [0..40]]; // Vincenzo Librandi, Jan 09 2014
CROSSREFS
Cf. A061434, A061439, and powers of cube root of k ceiling up: A017981 (k=2), A017984 (k=3), A017987 (k=4), A017990 (k=5), A017993 (k=6), A017996 (k=7), A018002 (k=9), this sequence (k=10), A018008 (k=11), A018011 (k=12), A018014 (k=13), A018017 (k=14), A018020 (k=15), A018023 (k=16), A018026 (k=17), A018029 (k=18), A018032 (k=19), A018035 (k=20), A018038 (k=21), A018041 (k=22), A018044 (k=23), A018047 (k=24).
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), May 16 2001
STATUS
approved