OFFSET
1,1
COMMENTS
Corresponding indices are 4, 5, 7, 8, 13, 14, 17, 23, 28, 29, 63, 80, 134, 233, 534, 732, 1963, 3896, 7792, 7987, 8312, ... with no more up to 2*10^4. - Charles R Greathouse IV, Mar 23 2014
Next index which produces a prime is 48979. - Robert G. Wilson v, May 21 2014
MATHEMATICA
a[n_?OddQ] := a[n] = Sum[a[k]*a[n - k], {k, 1, (n - 1)/2}]; a[n_?EvenQ] := a[n] = Sum[a[k]*a[n - k], {k, 1, n/2 - 1}] + (1/2)*a[n/2]*(1 + a[n/2]); a[0] = 0; a[1] = 1; Select[a@# & /@ Range@ 300, PrimeQ@# &] (* Robert G. Wilson v, May 20 2014, after Jean-François Alcover in A001190 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Charles R Greathouse IV, Mar 30 2008
STATUS
approved