A242139 - OEIS

%I #17 Aug 26 2014 04:01:16

%S 5,9,10,17,18,21,27,33,34,36,42,45,51,54,65,66,68,73,85,99,102,119,

%T 129,130,132,136,146,153,165,170,187,195,198,204,219,221,231,238,257,

%U 258,260,264,273,292,297,325,330,341,363,365,387,390,396,429,438,455

%N Decimal equivalents of A242138.

%o (PARI) isvper(v) = {nv = #v; if (isprime(nv), return (0)); fordiv(nv, d, if ((d > 1) && (d < nv), dv = vector(d, i, v[i]); pdv = []; for (k=1, nv/d, pdv = concat(pdv, dv)); if (pdv == v, return (1)););); return (0);}

%o isok(n) = {vn = binary(n); if (vecmin(vn) == vecmax(vn), return (0)); if (isvper(vn), return (1)); nbmax = #vn; for (k=1, nbmax, vn = concat(0, vn); if (isvper(vn), return (1));); return (0);} \\ _Michel Marcus_, Aug 25 2014

%K nonn,base

%O 1,1

%A _Felix Fröhlich_, May 05 2014

%E Missing terms 99, 102, 119 added and more terms from _Michel Marcus_, Aug 25 2014