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 A236514 #18 Mar 18 2014 00:01:07 %S A236514 2,3,7,23,31,47,79,127,157,191,223,317,367,379,383,479,727,751,887, %T A236514 1087,1151,1277,1279,1451,1471,1531,1663,1783,1789,1951,2297,2557, %U A236514 2927,3067,3259,3319,3581,3583,3967,4253,4349,5119,5231,5503,5807,5821,6079,6143,6271,6653,6871,6911,7039,7103,7151 %N A236514 Primes with a binary weight greater than or equal to the binary weight of their squares. %C A236514 Primes p such that A000120(p) = A000120(p^2): 2, 3, 7, 31, 79, 127, 157, 317, 379, 751, 1087, 1151, 1277, 1279,... %H A236514 Charles R Greathouse IV, <a href="/A236514/b236514.txt">Table of n, a(n) for n = 1..10000</a> %F A236514 Primes p such that A000120(p) >= A000120(p^2). %e A236514 2 is in this sequence because 2 is 10 in binary representation, and it has as many 1s as its square 4, which is 100 in binary. %t A236514 bc[n_] := DigitCount[n, 2][[1]]; Select[Range[7151], PrimeQ[#] && bc[#] >= bc[#^2] &] (* _Giovanni Resta_, Jan 28 2014 *) %t A236514 Select[Prime[Range[1000]], DigitCount[#, 2, 1] >= DigitCount[#^2, 2, 1] &] (* _Alonso del Arte_, Jan 28 2014 *) %o A236514 (PARI) is(n)=hammingweight(n^2)<=hammingweight(n) && isprime(n) \\ _Charles R Greathouse IV_, Mar 18 2014 %Y A236514 Cf. A077436, A094694. %K A236514 nonn,base %O A236514 1,1 %A A236514 _Irina Gerasimova_, Jan 27 2014