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A085428
Sum of the smallest and largest prime divisors of the n-th composite number.
0
4, 5, 4, 6, 7, 5, 9, 8, 4, 5, 7, 10, 13, 5, 10, 15, 6, 9, 7, 4, 14, 19, 12, 5, 21, 16, 7, 9, 13, 8, 25, 5, 14, 7, 20, 15, 5, 16, 9, 22, 31, 7, 33, 10, 4, 18, 13, 19, 26, 9, 5, 39, 8, 21, 18, 15, 7, 6, 43, 9, 22, 45, 32, 13, 7, 20, 25, 34, 49, 24, 5, 9, 14, 7
OFFSET
0,1
PROG
(PARI) maxpmindivc(n) = { for(x=4, n, s=0; forstep(p=2, x-1, 1, if(x%p==0 & isprime(p), s=p; break); ); forstep(p=x-1, 2, -1, if(x%p==0 & isprime(p), print1(s+p, ", "); break); ) ) }
CROSSREFS
Equals A056608(n) + A052369(n).
Sequence in context: A198817 A248624 A363195 * A053025 A010664 A074967
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Aug 13 2003
STATUS
approved