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%I #8 Apr 07 2020 08:48:23
%S 0,1,2,1,3,3,4,2,2,4,5,7,6,5,5,4,7,8,8,9,6,6,9,16,3,7,4,11,10,18,11,8,
%T 7,8,7,24,12,9,8,20,13,21,14,13,12,10,15,36,4,11,9,15,16,20,8,24,10,
%U 11,17,53,18,12,14,16,9,24,19,17,11,24,20,66,21,13,13
%N a(1) = 0, for n > 1 if n = prime(k), then a(n) = k, otherwise a(n) = Sum_{d|n, d<n} a(d).
%F a(1) = 0, a(n) = A049084(n) + Sum_{d|n, d<n} a(d) for n > 1.
%e a(20) = a(1) + a(2) + a(4) + a(5) + a(10) = 0 + 1 + (a(1)+a(2)) + 3 + (a(1)+a(2)+a(5)) = 0 + 1 + (0+1) + 3 + (0+1+3) = 1 + 1 + 3 + 4 = 9.
%o (PARI) lista(nn) = {my(v=vector(nn)); for(n=2, nn, v[n]=if(isprime(n), primepi(n), sumdiv(n, d, v[d]))); v; } \\ _Jinyuan Wang_, Apr 07 2020
%Y Cf. A049084.
%K nonn
%O 1,3
%A _Reinhard Zumkeller_, May 18 2003
%E a(36)-a(37) merged into a(36) by _Jinyuan Wang_, Apr 07 2020
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