A064011 Sum of distinct primes dividing n! + 1.

2, 3, 7, 5, 11, 110, 71, 722, 359, 329902, 39916801, 2834342, 75024430, 3790360510, 46271879, 1059865, 1538931, 123611150, 1713311273363902, 117897322430, 2703876255255, 93799610095770191, 148139754736864717

Offset: 1

Author

Jason Earls, Sep 07 2001

Keywords

• nonn

Examples

			a(6) = 110 since 6! + 1 = 721 = 7 * 103 and 7 + 103 = 110.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..139 (terms 1..60 from Harry J. Smith)

Crossrefs

Cf. A008472, A038507.

Programs

Mathematica

sopf[n_] := Plus @@ First @ Transpose @ FactorInteger[n]; sopf /@ Table[n! + 1 ,{n, 1, 23}] (* Amiram Eldar, Feb 03 2020 *)

PARI

sopf(n,s,fac,i)=fac=factor(n); for(i=1,matsize(fac)[1], s=s+fac[i,1]); return(s);
for(n=1,23,print(sopf(n!+1)))

PARI

sopf(n)= { local(f,s=0); f=factor(n); for(i=1, matsize(f)[1], s+=f[i, 1]); return(s) }
{ for (n=1, 60, write("b064011.txt", n, " ", sopf(n! + 1)) ) } \\ Harry J. Smith, Sep 06 2009

Formula

a(n) = A008472(A038507(n)). - Amiram Eldar, Feb 03 2020