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A338433
Values of n for which A070939(n^3) differs from A004221(n).
2
1, 20, 40, 80, 101, 126, 127, 159, 160, 161, 200, 201, 202, 203, 252, 253, 254, 255, 317, 318, 319, 320, 321, 322, 399, 400, 401, 402, 403, 404, 405, 406, 502, 503, 504, 505, 506, 507, 508, 509, 510, 511, 631, 632, 633, 634, 635, 636, 637, 638, 639, 640, 641, 642, 643, 644, 645
OFFSET
1,2
COMMENTS
Sequence gives the values of n for which the length of the binary representation of n^3 differs from ceiling(10*log_10(n)) rounded up.
The largest number not in the sequence is 158489319246111348520210137339 = floor(10^29.2). - Robert Israel, Oct 27 2020
MAPLE
filter:= n -> evalb(ilog2(n^3)+1 <> ceil(10*log[10](n))):
select(filter, [$1..1000]); # Robert Israel, Oct 27 2020
MATHEMATICA
Select[Range[1000], IntegerLength[#^3, 2] != Ceiling[10*Log10[#]] &] (* Amiram Eldar, Oct 27 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeremy Gardiner, Oct 27 2020
STATUS
approved