

A219227


a(n) is the sum of n addends nested as follows: floor(cbrt(floor(cbrt(...(n)...)))).


1



1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 72, 73
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OFFSET

1,2


COMMENTS

Its complement is 8, 28, 66, 128, 220, 348, 518, 519, 737, 1009, 1341, 1739, 2209, 2757, 3389, 4111, 4929, ..., .


LINKS

Table of n, a(n) for n=1..70.


EXAMPLE

a(8) = 9 because floor(cbrt(8))=2 and the floor(cbrt(floor(cbrt(8))))=1 as does the remaining six terms. So 2+7*1=8.


MATHEMATICA

f[n_] := Plus @@ Rest@ NestList[ Floor[#^(1/3)] &, n, n]; Array[f, 60]


CROSSREFS

Cf. A181092.
Sequence in context: A004727 A102352 A248182 * A007412 A270420 A220218
Adjacent sequences: A219224 A219225 A219226 * A219228 A219229 A219230


KEYWORD

nonn


AUTHOR

Robert G. Wilson v, Nov 15 2012


STATUS

approved



