OFFSET
1,2
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
a(4) = product of prime factors of composite numbers between 7 and 11 = 2 * 3 * (2 * 5) = 60.
MAPLE
a:= n-> mul(mul(i[1], i=ifactors(j)[2]), j=ithprime(n)+1..ithprime(n+1)-1):
seq(a(n), n=1..40); # Alois P. Heinz, May 29 2022
MATHEMATICA
Array[Times @@ Flatten@ Map[FactorInteger[#][[All, 1]] &, Range[#1 + 1, #2 - 1]] & @@ Prime[{#, # + 1}] &, 35] (* Michael De Vlieger, May 29 2022 *)
PROG
(PARI) a(n) = my(p=1); forcomposite(c=prime(n), prime(n+1), p*=factorback(factorint(c)[, 1])); p; \\ Michel Marcus, May 29 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Aug 30 2002
EXTENSIONS
Corrected and extended by Joshua Zucker, May 08 2006
Offset corrected by Alois P. Heinz, May 29 2022
STATUS
approved