1,1

Table of n, a(n) for n=1..6.

3 + 10 = 13, which is in the set.

7 + 10 = 17, which is in the set.

11 + 10 = 21 = 3 * 7, both of which are in the set.

13 + 10 = 23, which is in the set.

17 + 10 = 27 = 3^3, and 3 is in the set.

23 + 10 = 33 = 3 * 11, both of which are in the set.

Sequence in context: A310194 A310195 A310196 * A020618 A184865 A055211

Adjacent sequences: A020571 A020572 A020573 * A020575 A020576 A020577

nonn,fini,full

David W. Wilson

approved