A072581 a(n) = A000040(A072578(n)).

19, 53, 139, 193, 311, 313, 409, 577, 641, 719, 787, 809, 1033, 1061, 1097, 1171, 1193, 1289, 1627, 1637, 1657, 1669, 1693, 1699, 1747, 1811, 1877, 1889, 2083, 2089, 2153, 2161, 2179, 2203, 2213, 2273, 2311, 2659, 2689, 2753, 3169, 3677, 3727, 3733

Offset: 1

Author

Reinhard Zumkeller, Jun 23 2002

Keywords

• nonn
• base
• easy

Examples

			In binary representation 80 = '1010000' has five 0's and A000040(80) = 409 = '110011001' has five 1's: therefore 409 is a term.
		

Links

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

Crossrefs

Cf. A000040, A000120, A014499, A023416, A072439, A072578, A072580, A072582, A072584.

Programs

Mathematica

With[{m = 600}, Select[Transpose[{Range[m], Prime[Range[m]]}], DigitCount[First[#], 2, 0] == DigitCount[Last[#], 2, 1] &]][[;; , 2]] (* Amiram Eldar, Jul 28 2025 *)

Formula

A000120(a(n)) = A023416(A072578(n)) = A014499(n).