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.

A061247 Primes having only {0, 1, 8} as digits.

Original entry on oeis.org

11, 101, 181, 811, 881, 1181, 1801, 1811, 8011, 8081, 8101, 8111, 10111, 10181, 11801, 18181, 80111, 81001, 81101, 81181, 88001, 88801, 88811, 100801, 100811, 101081, 101111, 108011, 108881, 110881, 118081, 118801, 180001, 180181, 180811
Offset: 1

Views

Author

Amarnath Murthy, Apr 23 2001

Keywords

Comments

The intersection with A007500 is listed in A199328. - M. F. Hasler, Nov 05 2011

Examples

			a(6) = 1801, 1801 is a prime and consists of only 1, 8 and 0.
		

Crossrefs

Programs

  • Magma
    [NthPrime(n): n in [1..2*10^4] | forall{d: d in Intseq(NthPrime(n)) | d in [0, 1, 8]}]; // Vincenzo Librandi, May 15 2019
  • Maple
    N:= 1000: # to get the first N entries
    count:= 0:
    allowed:= {0,1,8}:
    nallowed:= nops(allowed):
    subst:= seq(i=allowed[i+1],i=0..nallowed-1);
    for d from 1 while count < N do
      for x1 from 1 to nallowed-1 while count < N do
        for t from 0 to nallowed^d-1  while count < N do
          L:= subs(subst,convert(x1*nallowed^d+t,base,nallowed));
          X:= add(L[i]*10^(i-1),i=1..d+1);
          if isprime(X) then
              count:= count+1;
              A[count]:= X;
          fi
    od od od:
    seq(A[n],n=1..N); # Robert Israel, Apr 20 2014
  • Mathematica
    Select[Prime[Range[50000]],Length[Union[{0,1,8},IntegerDigits[ # ]]] == 3&] (* Stefan Steinerberger, Jun 10 2007 *)
    Select[FromDigits/@Tuples[{0,1,8},6],PrimeQ] (* Harvey P. Dale, Jan 12 2016 *)
  • PARI
    a(n=50, L=[0, 1, 8], show=0)={my(t); for(d=1, 1e9, u=vector(d, i, 10^(d-i))~; forvec(v=vector(d, i, [1+(i==1 && !L[1]), #L]), ispseudoprime(t=vector(d, i, L[v[i]])*u) || next; show && print1(t", "); n-- || return(t)))} \\ M. F. Hasler, Nov 05 2011
    

Extensions

Corrected and extended by Stefan Steinerberger, Jun 10 2007