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Convolution of A023531 and primes.
1

%I #14 Dec 28 2015 20:10:17

%S 0,2,3,5,9,14,18,24,32,39,51,57,71,85,94,108,124,142,152,176,193,205,

%T 229,249,271,295,315,336,364,386,408,444,468,490,526,561,583,617,663,

%U 681,717,745,781,831,862,894,924,968,1006,1050,1100,1138,1174

%N Convolution of A023531 and primes.

%H Robert Israel, <a href="/A023567/b023567.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = Sum_{i=0..n-1} A023531(n-i)*p(i+1) where p(i) is the i-th prime.

%p Primes:= select(isprime, [2,seq(i,i=3..1000,2)]):

%p seq(add(Primes[n - i*(i+3)/2],i=1..floor((sqrt(1+8*n)-3)/2)), n=2..nops(Primes)); # _Robert Israel_, Dec 28 2015

%o (PARI) vector(20,x,c=0;j=x;t=3;while(j>1,c+=prime(j-1);j-=t;t+=1);c)

%K nonn

%O 1,2

%A _Clark Kimberling_

%E Corrected (term 781 was missing) by _Jeremy Gardiner_, Feb 05 2014