A330291 - cp's OEIS frontend

A330291 a(1) = 1; for n > 1, a(n) is the smallest prime divisor of the number formed by the concatenation of a(1) to a(n-1) that has not previously appeared in the sequence.

n	a(n)
1	1
2	1
3	11
4	101
5	3
6	17
7	65358901
8	7
9	109
10	10193590070216413001
11	359
12	4007
13	149
14	43787
15	169031777
16	67
17	13
18	14767
19	30323
20	151651
21	1194421
22	31008087256045370298219860945197217288544368471059741857398977350440454626775436666667
23	1087
24	27457
25	19301
26	23
27	22349

[1, 1, 11, 101, 3, 17, 65358901, 7, 109, 10193590070216413001, 359, 4007, 149, 43787, 169031777, 67, 13, 14767, 30323, 151651, 1194421, 31008087256045370298219860945197217288544368471059741857398977350440454626775436666667, 1087, 27457, 19301, 23, 22349]

cp's OEIS Frontend

A330291 a(1) = 1; for n > 1, a(n) is the smallest prime divisor of the number formed by the concatenation of a(1) to a(n-1) that has not previously appeared in the sequence.

Table of values

List of values