login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A110373
a(n) = Sum_{prime p <= n} n!/p.
7
1, 5, 20, 124, 744, 5928, 47424, 426816, 4268160, 50578560, 606942720, 8369256960, 117169597440, 1757543961600, 28120703385600, 498974747443200, 8981545453977600, 177051737331302400, 3541034746626048000
OFFSET
2,2
LINKS
EXAMPLE
a(7) = 7!(1/2 + 1/3 + 1/5 + 1/7) = 5928.
MAPLE
a:=proc(n) local s, i: s:=0: for i from 2 to n do if isprime(i)=true then s:=s+1/i else s:=s: fi: od: n!*s: end: seq(a(n), n=2..23); # Emeric Deutsch, Jul 24 2005
MATHEMATICA
Table[n! Total[1/Prime[Range[PrimePi[n]]]], {n, 20}] (* Harvey P. Dale, Mar 06 2017 *)
CROSSREFS
Cf. A110374.
Sequence in context: A208941 A209069 A301952 * A081067 A318250 A337292
KEYWORD
easy,nonn
AUTHOR
Amarnath Murthy, Jul 24 2005
EXTENSIONS
More terms from Emeric Deutsch, Jul 24 2005
STATUS
approved