A333811 a(0) = 0; for n > 0, a(n) is the smallest positive integer not yet appearing in the sequence such that a(n-1)^a(n) contains as a substring either a(n-1) or a(n).

0, 1, 2, 5, 3, 7, 4, 6, 8, 9, 11, 15, 12, 14, 13, 10, 16, 17, 21, 20, 25, 18, 23, 19, 22, 24, 26, 29, 30, 28, 31, 27, 32, 33, 35, 34, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 47, 46, 48, 50, 49, 51, 52, 53, 55, 54, 56, 57, 59, 58, 61, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70

Offset

0,3

Comments

a(3) = 5 as a(2) ^ a(3) = 2 ^ 5 = 32 which contains '2' as a substring.

a(4) = 3 as a(3) ^ a(4) = 5 ^ 3 = 125 which contains '5' as a substring.

a(5) = 7 as a(4) ^ a(5) = 3 ^ 7 = 2187 which contains '7' as a substring.

Links

Table of n, a(n) for n=0..70.

Rémy Sigrist, PARI program for A333811

Prog

(PARI) See Links section.

Crossrefs

Cf. A333774, A333775, A332795, A332703.

Sequence in context: A342659 A253924 A141410 * A352588 A257906 A354575

Adjacent sequences: A333808 A333809 A333810 * A333812 A333813 A333814

Keyword

nonn,base

Author

Scott R. Shannon, Apr 05 2020

Status

approved