A215138 Numbers n such that n > d(n)^2/2 where d = A000005.

1, 3, 5, 7, 9, 10, 11, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85

Offset: 1

Author

Gerasimov Sergey, Aug 04 2012

Keywords

• nonn

Comments

n <= A000005(n)^2/2 begins: 2, 4, 6, 8, 12, 18, 24, 30, 36, 48, 60, 72, 120.

Examples

			a(1)=1 because 1 > A000005(1)^2/2 = 1^2/2 = 1/2;
a(2)=3 because 3 > A000005(3)^2/2 = 2^2/2 = 2;
a(3)=5 because 5 > A000005(5)^2/2 = 2^2/2 = 2;
a(4)=7 because 7 > A000005(7)^2/2 = 2^2/2 = 2;
a(5)=9 because 9 > A000005(9)^2/2 = 3^2/2 = 9/2;
a(6)=10 because 10 > A000005(1)^2/2 = 4^2/2 =8.
		

Crossrefs

Cf. A035033, A035035.

Programs

PARI

is(n)=numdiv(n)^2/2