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.

2, 8, 48, 816, 74256, 2335722480, 3265147014612865200

Offset

1,1

Links

Table of n, a(n) for n=1..7.

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

Cf. A079803, A079804, A079805.

Sequence in context: A280133 A192411 A179563 * A009741 A322309 A009745

Adjacent sequences: A079799 A079800 A079801 * A079803 A079804 A079805

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