A072579 In binary representation: k has the same number of 1's as the k-th prime has 0's.

1, 7, 13, 26, 37, 41, 42, 45, 49, 50, 58, 59, 62, 69, 70, 74, 78, 79, 87, 103, 105, 107, 110, 114, 118, 121, 134, 139, 141, 142, 145, 147, 158, 161, 162, 164, 165, 168, 175, 185, 189, 198, 202, 203, 213, 214, 223, 227, 232, 234, 243, 267, 275, 282, 289, 292

Offset: 1

Author

Reinhard Zumkeller, Jun 23 2002

Keywords

• nonn
• base
• easy

Examples

			In binary representation 70 = '1000110' has three 1's and A000040(70) = 349 = '101011101' has three 1's: therefore 70 is a term.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000120, A023416, A035103, A049084, A071600, A072577, A072578, A072582.

Programs

Mathematica

Select[Range[300],DigitCount[#,2,1]==DigitCount[Prime[#],2,0]&] (* Harvey P. Dale, May 02 2012 *)

Formula

A023416(A072582(n)) = A000120(a(n)) = A035103(n).

a(n) = A049084(A072582(n)).