A092839 Indices of primes in A001003.

3, 4, 6, 10, 216

Offset: 1

Author

Eric W. Weisstein, Mar 07 2004

Keywords

• nonn
• more

Comments

a(6), if it exists, is > 1.5*10^6. - Robert Price, Apr 16 2014

Links

• Eric Weisstein's World of Mathematics, Super Catalan Number
• Eric Weisstein's World of Mathematics, Integer Sequence Primes

Crossrefs

Cf. A001003, A092840.

Programs

PARI

s(m)= { if (m==1, return(a1)); if (m==2, return(a2)); r = (3*(2*m - 3)*a2 - (m - 3)*a1)/m; a1=a2; a2=r; return(r); }
{ a1=1; a2=1; n=0; for (m=1, 300, a=s(m); if (isprime(a), n++; print1(m, ", "))); } \\ Harry J. Smith, Jun 21 2009