OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
MATHEMATICA
Table[Ceiling[21^(n/3)], {n, 0, 40}] (* Vincenzo Librandi, Jan 10 2014 *)
PROG
(Magma) [Ceiling(21^(n/3)): n in [0..40]]; // Vincenzo Librandi, Jan 10 2014
CROSSREFS
Cf. 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), A018005 (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), this sequence (k=21), A018041 (k=22), A018044 (k=23), A018047 (k=24).
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, Jan 10 2014
STATUS
approved