

A277383


Each even integer k is followed by k odd integers.


1



0, 2, 1, 3, 4, 5, 7, 9, 11, 6, 13, 15, 17, 19, 21, 23, 8, 25, 27, 29, 31, 33, 35, 37, 39, 10, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 12, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 14, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 16, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133
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OFFSET

1,2


COMMENTS

The sequence starts with a(1) = 0 and was always extended with the smallest nonnegative integer not yet present that does not lead to a contradiction.


LINKS

JeanMarc Falcoz, Table of n, a(n) for n = 1..7162


EXAMPLE

As a(1) = 0, a(2) cannot be an odd term: thus a(2) = 2 (the smallest available nonnegative even integer); now as a(3) and a(4) must be odd integers we have a(3) = 1 and a(4) = 3 (again, the smallest available nonnegative odd integers); now a(5) = 4, forcing the next 4 integers to be odd, thus a(6) = 5, a(7) = 7, a(8) = 9 and a(9) = 11; etc.


MATHEMATICA

Table[Prepend[2 Range[# (# + 1) + 1, # (# + 1) + 2 n] &@ (n  1)  1, 2 n], {n, 0, 8}] // Flatten (* Michael De Vlieger, Oct 12 2016 *)


CROSSREFS

Cf. A002378, A002522 (position of evens in a(n)).
Sequence in context: A048212 A282864 A277518 * A077159 A277677 A075379
Adjacent sequences: A277380 A277381 A277382 * A277384 A277385 A277386


KEYWORD

nonn,base


AUTHOR

Eric Angelini and JeanMarc Falcoz, Oct 12 2016


STATUS

approved



