OFFSET
0,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..21 (extended using Kim Walisch's primesum; terms 0..19 from Daniel Suteu)
Kim Walisch, primesum program.
FORMULA
EXAMPLE
a(2) = 3 + 5 = 8.
a(3) = 7 + 11 + 13 + 17 + 19 + 23 = 90.
MATHEMATICA
Table[Plus @@ Table[Prime[i], {i, PrimePi[n!] + 1, PrimePi[(n + 1)!]}], {n, 0, 10}]
PROG
(PARI) a(n) = { my(s = 0); forprime(p=n!+1, (n+1)!, s+=p); s; } \\ Iain Fox, Nov 23 2017
(Perl) use ntheory ':all'; for(0..100) { print "a($_) = ", sum_primes(factorial($_)+1, factorial($_+1)), "\n"; } # Daniel Suteu, Nov 15 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Olivier Gérard, Oct 22 2017
EXTENSIONS
a(11)-a(13) from Iain Fox, Nov 23 2017
a(14) from Iain Fox, Nov 28 2017
a(15)-a(17) from Daniel Suteu, Nov 15 2018
STATUS
approved