A063961 Numbers k such that z(k) = j(k), where z(k) = sopf(k - d(k)), j(k) = d(sopf(k) + k), sopf(k) = A008472(k) and d(k) = A000005(k).
6, 24, 40, 516, 532, 679, 1219, 1581, 1790, 2196, 2212, 3060, 3182, 4120, 4266, 5816, 9084, 9812, 11648, 11911, 13532, 16488, 16904, 17016, 17436, 20448, 20460, 21129, 23962, 25356, 26016, 34307, 34856, 41624, 42348, 44392, 48420, 50696
Offset: 1
Keywords
Links
- Harry J. Smith, Table of n, a(n) for n = 1..375
Programs
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PARI
sumprime(n,s,fac,i) = fac=factor(n); for(i=1,matsize(fac)[1],s=s+fac[i,1]); return(s); z(n)=sumprime(n-numdiv(n)); d(n)=numdiv(sumprime(n)+n); for(n=1,10^6, if(d(n)==z(n),print(n)))
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PARI
sumprime(n)= { local(f,s=0); f=factor(n); for(i=1, matsize(f)[1], s+=f[i, 1]); return(s) } z(n)= { sumprime(n - numdiv(n)) } d(n)= { numdiv(sumprime(n) + n) } { n=0; for (m=1, 10^9, if(d(m)==z(m), write("b063961.txt", n++, " ", m); if (n==375, break)) ) } \\ Harry J. Smith, Sep 04 2009