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.

A092570 Primes p which become a prime q under transformation of inner bits of binary representation in A092569. In binary representation of p, transformation of inner bits, 1 <-> 0, gives binary representation of q.

Original entry on oeis.org

2, 3, 5, 7, 11, 13, 17, 19, 29, 31, 37, 43, 53, 59, 79, 83, 89, 103, 109, 113, 151, 157, 173, 191, 193, 211, 227, 233, 269, 277, 281, 307, 311, 337, 347, 349, 359, 367, 379, 389, 401, 409, 419, 421, 431, 457, 461, 487, 491, 499, 523, 569, 599, 607, 617, 653, 659
Offset: 1

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Author

Zak Seidov, Feb 28 2004

Keywords

Examples

			307 and 461 are terms because 307_10 = 100110011_2, transformation of inner bits gives 100110011_2 -> 111001101_2 = 461_10.
		

Crossrefs

Cf. A092569.

Programs

  • Mathematica
    ptibQ[n_]:=Module[{id=IntegerDigits[n,2],f,l,r},f=id[[1]];l=id[[-1]];r=Most[Rest[id]];PrimeQ[FromDigits[Join[{f},r/.{1->0,0->1},{l}],2]]]; Select[Prime[Range[200]],ptibQ] (* Harvey P. Dale, Jul 16 2025 *)
  • PARI
    T(p)={pow2=2;v=binary(p);L=#v-1;forstep(k=L,2,-1,if(v[k],p-=pow2,p+=pow2);pow2*=2);return(p)};
    forprime(p=2,659,if(isprime(T(p)),print1(p,", ")))
    \\ Washington Bomfim, Jan 18 2011