OFFSET
1,3
FORMULA
a(n) = a(Pi(n))+1.
a(n) = A060197(n) - 2. - Filip Zaludek, Dec 10 2016
MATHEMATICA
Table[Length[NestWhileList[PrimePi[#]&, n, #!=1&]]-1, {n, 110}] (* Harvey P. Dale, Dec 24 2018 *)
PROG
(PARI) for(n=2, 150, s=n; t=0; while(s!=1, t++; s=sum(i=2, s, isprime(i)); if(s==1, print1(t, ", "); ); ))
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, May 31 2002
STATUS
approved