A183856 n+floor(sqrt(3n-2)); complement of A143975.

2, 4, 5, 7, 8, 10, 11, 12, 14, 15, 16, 17, 19, 20, 21, 22, 24, 25, 26, 27, 28, 30, 31, 32, 33, 34, 35, 37, 38, 39, 40, 41, 42, 44, 45, 46, 47, 48, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 70, 71, 72, 73, 74, 75, 76, 77, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 102, 103, 104, 105, 106

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

a(n+1) - a(n) = 2 if n is in A000212, 1 otherwise. - Robert Israel, Jun 04 2019

Maple

seq(seq(i+k, i=ceil((k^2+2)/3) .. ((k+1)^2+1)/3), k=1..10); # Robert Israel, Jun 04 2019

Mathematica

Array[#+Floor[Sqrt[3#-2]]&, 100] (* Harvey P. Dale, Mar 15 2013 *)

Crossrefs

Cf. A000212, A143975.

Sequence in context: A092289 A079358 A184014 * A183869 A224731 A289036

Adjacent sequences: A183853 A183854 A183855 * A183857 A183858 A183859

Keyword

nonn,easy

Author

Clark Kimberling, Jan 07 2011

Status

approved