A184012 n + floor(sqrt(5n-4)); complement of A184013.

2, 4, 6, 8, 9, 11, 12, 14, 15, 16, 18, 19, 20, 22, 23, 24, 26, 27, 28, 29, 31, 32, 33, 34, 36, 37, 38, 39, 40, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 68, 69, 70, 71, 72, 73, 74, 76, 77, 78, 79, 80, 81, 82, 84, 85, 86, 87, 88, 89, 90, 92, 93, 94, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 106, 107, 108, 110, 111, 112, 113, 114, 115, 116, 117, 118, 120, 121, 122

Offset

1,1

Links

Table of n, a(n) for n=1..100.

Formula

a(n) = n + floor(sqrt(5n-4))

Mathematica

a=5; b=-4;
Table[n+Floor[(a*n+b)^(1/2)], {n, 100}]
Table[n-1+Ceiling[(n*n-b)/a], {n, 70}]

Crossrefs

Cf. A184013.

Sequence in context: A036627 A191982 A080037 * A186354 A186149 A298861

Adjacent sequences: A184009 A184010 A184011 * A184013 A184014 A184015

Keyword

nonn,easy

Author

Clark Kimberling, Jan 08 2011

Status

approved