This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A072439 #15 Aug 03 2023 03:44:22 %S A072439 2,5,41,67,73,83,97,113,193,197,211,269,281,283,353,389,521,523,547, %T A072439 563,587,593,601,647,661,691,929,937,1061,1063,1097,1109,1117,1123, %U A072439 1289,1319,1361,1381,1489,1549,1559,1567,1571,1579,1597,1801,1873,2069 %N A072439 Primes prime(k) such that the number of binary 1's in prime(k) equals the number of binary 1's in k. %H A072439 Amiram Eldar, <a href="/A072439/b072439.txt">Table of n, a(n) for n = 1..10000</a> %F A072439 A000120(a(n)) = A000120(A071600(n)) = A014499(n). %F A072439 A090455(A049084(a(n))) = 0. %F A072439 a(n) = A000040(A071600(n)). %e A072439 In binary representation 13 and A000040(13)=41 have three 1's: 13='1101' and 41='101001', therefore 41 is a term. %t A072439 Prime[Select[Range[400], DigitCount[#, 2, 1] == DigitCount[Prime[#], 2, 1] &]] (* _Amiram Eldar_, Aug 03 2023 *) %o A072439 (PARI) isok(p) = isprime(p) && ((hammingweight(p) == hammingweight(primepi(p)))); \\ _Michel Marcus_, Jun 14 2021 %Y A072439 Cf. A000040, A000120, A014499, A033548, A049084, A071600, A090455. %K A072439 nonn,base %O A072439 1,1 %A A072439 _Reinhard Zumkeller_, Jun 17 2002