cp's OEIS Frontend

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.

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A095322 Primes in whose binary expansion the number of 1 bits is > 4 + number of 0 bits.

Original entry on oeis.org

31, 127, 191, 223, 239, 251, 367, 379, 383, 431, 439, 443, 463, 479, 487, 491, 499, 503, 509, 751, 863, 887, 983, 991, 1013, 1019, 1021, 1151, 1277, 1279, 1399, 1439, 1471, 1487, 1499, 1511, 1523, 1531, 1663, 1723, 1759, 1783, 1787, 1789, 1823
Offset: 1

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Author

Antti Karttunen, Jun 04 2004

Keywords

Crossrefs

Complement of A095323 in A000040. Subset of A095318. Subset: A095284. Cf. also A095324.

Programs

  • Mathematica
    btsQ[n_]:=Module[{idn2=IntegerDigits[n,2]},Count[idn2,1]>4+Count[ idn2,0]]; Select[Prime[Range[300]],btsQ] (* Harvey P. Dale, Nov 12 2011 *)
  • PARI
    B(x) = { nB = floor(log(x)/log(2)); b1 = 0; b0 = 0;
    for(i = 0, nB, if(bittest(x,i), b1++;, b0++;); );
    if(b1 > (4+b0), return(1);, return(0););};
    forprime(x = 2, 1823, if(B(x), print1(x, ", "); ); ); \\ Washington Bomfim, Jan 12 2011

A095325 Number of A095323-primes in range ]2^n,2^(n+1)].

Original entry on oeis.org

1, 2, 2, 4, 7, 12, 19, 30, 67, 102, 211, 340, 722, 1146, 2329, 3992, 8423, 14010, 29281, 49682, 105893, 180016, 378928, 654049, 1385920, 2387358, 5069466, 8820563, 18782814, 32732736, 69445570, 121964573, 259680216
Offset: 1

Views

Author

Antti Karttunen, Jun 04 2004

Keywords

Comments

Ratios a(n)/A036378(n) converge as: 1, 1, 1, 0.8, 1, 0.923077, 0.826087, 0.697674, 0.893333, 0.744526, 0.827451, 0.732759, 0.827982, 0.710918, 0.768647, 0.699247, 0.783608, 0.687102, 0.757888, 0.675156, 0.754568, 0.671161, 0.737633, 0.663458, 0.731696, 0.654834, 0.721397, 0.650393, 0.716702, 0.645647, 0.70731, 0.640787, 0.703124
Ratios a(n)/A095054(n) converge as: 1, 1, 1, 1, 1, 1.2, 0.95, 0.9375, 1.030769, 1.051546, 1.039409, 1.017964, 1.005571,1.014159, 0.97816, 1.009866, 1.018993, 1.007117, 1.009864, 1.002381,1.003497, 1.006182, 1.005197, 1.005142, 1.001903, 1.002926, 1.004856,1.004575, 1.004471, 1.003502, 1.001392, 1.002787, 1.002428

Crossrefs

a(n) = A036378(n)-A095324(n).
Showing 1-2 of 2 results.