OFFSET
1,1
COMMENTS
In the Honaker-Caldwell link there is the example
2030507011013017019023029031037041043047053059061067071073079083089097
with 70 digits. It consists of the sequence of primes less than 100 separated by zeros.
LINKS
G. L. Honaker, Jr. and Chris Caldwell, Prime Curios!: 20305...89097 (70-digits)
EXAMPLE
10103 is a term because 101 and 3 are primes separated by a single zero.
MATHEMATICA
Take[Select[FromDigits[Flatten[IntegerDigits/@#]]&/@(Riffle[#, 0]&/@Tuples[Prime[ Range[ 30]], 2]), PrimeQ]//Sort, 50] (* Harvey P. Dale, Jul 05 2022 *)
PROG
(PARI) cut(d, b) = {my(nb = hammingweight(b), vs = vector(nb+1, k, ""), iz = 0, ind = 1); for (i=1, #d, if (d[i] == 0, iz ++; if (b[iz], ind++, vs[ind] = concat(vs[ind], d[i])), vs[ind] = concat(vs[ind], d[i]); ); ); apply(x->eval(x), vs); }
isok(n) = {if (isprime(n), my(d = digits(n), dz = select(x->(x==0), d, 1), nbz = #dz); if (! nbz, return (0)); if (nbz > 1, for (k=2, #dz, if (dz[k] == dz[k-1] + 1, return (0)); ); ); for (i=1, 2^nbz-1, my(b = binary(i)); while (#b < nbz, b = concat(0, b)); my(vstr = cut(d, b)); if (#select(x->isprime(x), vstr) == #vstr, return (1)); ); ); } \\ Michel Marcus, Aug 07 2019
CROSSREFS
KEYWORD
nonn,base,nice
AUTHOR
Bernard Schott, Jul 12 2019
EXTENSIONS
Missing term 10903 and more terms from Michel Marcus, Aug 07 2019
STATUS
approved