OFFSET
1,1
LINKS
MATHEMATICA
Table[ sum = 0; For[i = 1, i <= Prime[n] , i++, sum = sum*2;
If[! PrimeQ[i], sum++]]; IntegerString[sum, 2], {n, 1, 20}] (* Robert Price, Apr 03 2019 *)
PROG
(PARI) a(n) = fromdigits(vector(prime(n), k, !isprime(k)), 10); \\ Michel Marcus, Apr 04 2019
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Omar E. Pol, Apr 08 2008
EXTENSIONS
a(12)-a(13) from Robert Price, Apr 03 2019
STATUS
approved