A074124 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 sum of n-th group.

4, 6, 165, 49, 143, 962, 884, 1577, 6992, 3161, 3565, 1924, 8159, 18834, 41877, 2332, 2360, 2867, 34304, 184245, 70883, 15405, 8798, 107512, 216213, 136855, 49131, 31030, 105621, 783994, 49911, 6288, 426070, 571429, 639210, 404982

Offset

1,1

Links

Table of n, a(n) for n=1..36.

Prog

(PARI) c=3:for(n=1, 50, s=0:while((s==0||s%prime(n)>0), c=c+1: if(isprime(c), c=c+1):s=s+c):print1(s", "))

Crossrefs

Cf. A074125, A074126, A074127.

Sequence in context: A070155 A280778 A197882 * A303161 A070156 A298147

Adjacent sequences: A074121 A074122 A074123 * A074125 A074126 A074127

Keyword

nonn

Author

Amarnath Murthy, Aug 27 2002

Extensions

Corrected and extended by Ralf Stephan, Mar 22 2003

Status

approved