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A074126
Group the composite numbers so that the sum of the n-th group is a multiple of the n-th prime: (4), (6), (8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 22), (24, 25), (26, 27, 28, 30, 32), (33, 34, ...), ... Sequence gives the number of terms in each group.
3
1, 1, 11, 2, 5, 21, 13, 18, 53, 18, 18, 9, 34, 63, 105, 5, 5, 6, 66, 259, 78, 16, 9, 103, 179, 100, 34, 21, 69, 431, 24, 3, 193, 233, 235, 138, 172, 64, 171, 161, 229, 51, 44, 598, 363, 733, 924, 362, 224, 99, 77, 54, 142, 261, 332, 5, 216, 592, 67, 72, 1140, 86, 336, 91, 43
OFFSET
1,3
PROG
(PARI) { n=3; for(k=1, 100, r=0; s=0; c=0; while(!s||(s%prime(k)>0), if(!isprime(n), s=s+n; c++ ; if(!r, r=n) ); n=n+1 ); print1(c", ") ) } - R. J. Mathar, Nov 10 2006
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Aug 27 2002
EXTENSIONS
Corrected and extended by R. J. Mathar, Nov 10 2006
STATUS
approved