

A080588


a(n) is smallest nonnegative integer which is consistent with sequence being monotonically increasing and satisfying a(a(n)) = 4n.


4



0, 2, 4, 5, 8, 12, 13, 14, 16, 17, 18, 19, 20, 24, 28, 29, 32, 36, 40, 44, 48, 49, 50, 51, 52, 53, 54, 55, 56, 60, 61, 62, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 84, 88, 92, 96, 100, 104, 108, 112, 113, 114, 115, 116, 120, 124, 125
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

Equivalently: a(n) is taken to be the smallest positive integer greater than a(n1) which is consistent with the condition "n is a member of the sequence if and only if a(n) is a multiple of 4".
The sequence of even numbers shares many of the properties of this sequence.


LINKS



FORMULA

a(a(n)) = 4n. a(2^k) = 2^(k+1).


CROSSREFS



KEYWORD

nonn,easy,nice


AUTHOR



STATUS

approved



