OFFSET
1,2
COMMENTS
FORMULA
a(2n) = prime(n) and a(2n+1)= product of composite numbers between prime(n) and prime(n+1).
MAPLE
A109919 := proc(n) local p; if n mod 2 = 0 then ithprime(n/2) ; elif n = 1 then 1 ; else p := ithprime((n-1)/2) ; mul(i, i=p+1..nextprime(p)-1) ; fi ; end: for n from 1 to 80 do printf("%d, ", A109919(n)) ; od ; # R. J. Mathar, May 02 2007
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Amarnath Murthy, Jul 16 2005
EXTENSIONS
More terms from R. J. Mathar, May 02 2007
STATUS
approved