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”).

A067111
Floor[ Product of first n primes / Sum of first n primes].
2
1, 1, 3, 12, 82, 732, 8801, 125970, 2230928, 50152660, 1253503063, 37668721496, 1278362451795, 46557869507722, 1874663971306376, 85535849021496180, 4369909886714119634, 234108545627558824317, 13835073153310329323730
OFFSET
1,3
LINKS
FORMULA
a(n) = floor(A002110(n)/A007504(n)). - Michel Marcus, Jul 16 2020
EXAMPLE
a(4) = floor(2*3*5*7/17) = floor(210/17) = 12.
MATHEMATICA
Table[ Floor[ Product[ Prime[i], {i, 1, n} ] / Sum[ Prime[i], {i, 1, n} ]], {n, 1, 22} ]
Module[{nn=20, p, pr, sm}, p=Prime[Range[nn]]; pr=FoldList[Times, p]; sm=Accumulate[p]; Floor[ pr/sm]] (* Harvey P. Dale, Sep 01 2023 *)
PROG
(PARI) { t=1; s=0; for (n=1, 100, p=prime(n); t*=p; s+=p; write("b067111.txt", n, " ", floor(t/s)) ) } \\ Harry J. Smith, May 23 2010
CROSSREFS
Cf. A002110 (product) and A007504 (sum) of first n primes.
Sequence in context: A357665 A224608 A023881 * A171186 A229421 A376012
KEYWORD
easy,nonn
AUTHOR
Amarnath Murthy, Jan 08 2002
EXTENSIONS
More terms from Robert G. Wilson v, Jan 08 2002
STATUS
approved