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

1,1

Links

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

Formula

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

Example

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

Mathematica

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

Prog

(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

Crossrefs

Cf. A008472, A038507.

Sequence in context: A117928 A333086 A359504 * A050367 A354201 A332210

Adjacent sequences: A064008 A064009 A064010 * A064012 A064013 A064014

Keyword

nonn

Author

Jason Earls, Sep 07 2001

Status

approved