Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #5 Mar 31 2012 13:50:44
%S 1,2,2,2,4,5,9,11,16,22,26,30,38,45,51,59,68,77,83,96,106,115,127,139,
%T 151,165,177,190,204,221,236,250,267,286,304,323,339,361,382,400,421,
%U 440,465,486,512,533,556,580,604,633,656,686,713,739,769,797,827,856
%N Number of primes p such that p can be expressed as the sum of distinct primes with largest prime in the sum = n-th prime.
%e For n=5; 11 is the 5th prime. 11=11, 13= 2+11, 19= 3+5+11, 23= 2+3+7+11 = 5+7+11. 11 and 13,19,23 are primes. so a(5)=4.
%o (PARI) limit = 70; M = sum(i = 1, limit, prime(i)); v = vector(M); primeSum = 0; forprime (n = 1, prime(limit), count = 1; forstep (i = primeSum, 1, -1, if (v[i], if (isprime(i + n), count = count + 1); v[i + n] = 1)); v[n] = 1; print(count); primeSum = primeSum + n)
%Y Cf. A082533, A082534.
%K easy,nonn
%O 1,2
%A _Naohiro Nomoto_, May 02 2003
%E More terms from _David Wasserman_, Sep 16 2004