A074145 a(1) = 1; for n>1, a(n) is the smallest previously unused natural number such that a(n) divides the sum of next a(n) terms.

1, 2, 3, 5, 4, 6, 7, 8, 15, 9, 10, 11, 12, 19, 13, 23, 14, 16, 17, 18, 27, 20, 30, 31, 24, 21, 22, 36, 25, 26, 37, 28, 47, 39, 29, 33, 32, 51, 44, 34, 35, 56, 38, 40, 41, 42, 63, 48

Offset

1,2

Comments

4 comes after 5 hence the next terms after 5 are so chosen that the property holds for 4 as well.

The next term a(49) does not exist, so there are no more terms. This is because a(25)=24 and a(27)=22 both must divide a(49). Assuming that a(49)=x, this leads to 867+x=24a and 824+x=22b for some integers a and b. Subtracting, we get 43=24a-22b, which is a contradiction. - John W. Layman, Jul 29 2003

Links

Table of n, a(n) for n=1..48.

Example

5 divides the sum (4 + 6 +7 +8 + 15) of the next five terms and 4 does so for (6+7+8+15).

Crossrefs

Cf. A074137, A074138.

Sequence in context: A131142 A131141 A130981 * A299237 A257676 A257677

Adjacent sequences: A074142 A074143 A074144 * A074146 A074147 A074148

Keyword

fini,full,nonn

Author

Amarnath Murthy, Aug 28 2002

Extensions

More terms from John W. Layman, Jul 29 2003

Status

approved