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%I #5 Dec 05 2013 19:55:33
%S 1,1,11,2,5,21,13,18,53,18,18,9,34,63,105,5,5,6,66,259,78,16,9,103,
%T 179,100,34,21,69,431,24,3,193,233,235,138,172,64,171,161,229,51,44,
%U 598,363,733,924,362,224,99,77,54,142,261,332,5,216,592,67,72,1140,86,336,91,43
%N 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.
%o (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
%Y Cf. A074124, A074125, A074127.
%K nonn
%O 1,3
%A _Amarnath Murthy_, Aug 27 2002
%E Corrected and extended by _R. J. Mathar_, Nov 10 2006