A072580 a(n) = A000040(A072577(n)).

11, 13, 71, 79, 89, 107, 127, 131, 139, 157, 179, 181, 227, 229, 331, 337, 419, 421, 433, 457, 461, 487, 491, 787, 797, 809, 811, 821, 823, 853, 877, 919, 977, 1163, 1181, 1213, 1223, 1231, 1277, 1279, 1459, 1487, 1523, 1667, 1697, 1733, 1741, 1861, 1867

Offset: 1

Author

Reinhard Zumkeller, Jun 23 2002

Keywords

• nonn
• base
• easy

Examples

			In binary representation 20 and A000040(20) = 71 have three 0's: 13 = '10100' and 71 = '1000111', therefore 71 is a term.
		

Links

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

Crossrefs

Cf. A000040, A023416, A035103, A072439, A072577, A072581, A072582, A072584.

Programs

Mathematica

With[{m = 300}, Select[Transpose[{Range[m], Prime[Range[m]]}], Equal @@ DigitCount[#, 2, 0] &]][[;; , 2]] (* Amiram Eldar, Jul 27 2025 *)

Formula

A023416(a(n)) = A023416(A072577(n)) = A035103(n).