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A079802
Group the prime numbers so that the sum of the terms of the n-th group is a multiple of that of the (n-1)-st group: (2), (3,5), (7,11,13,17), (19,23,29,31,37...,79,83), ...; a(n) = sum of n-th group.
3
2, 8, 48, 816, 74256, 2335722480, 3265147014612865200
OFFSET
1,1
PROG
(PARI) p=2; print1(s=p, ", "); while(s<10^9, p=nextprime(p+1); a=p; while(a%s>0, p=nextprime(p+1); a=a+p); print1(s=a, ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Feb 05 2003
EXTENSIONS
a(5), a(6) and PARI code from Klaus Brockhaus, Feb 13 2003
a(7) from Ryan Propper, Aug 29 2005
STATUS
approved