A276070 Each digit of the absolute difference |a(n+1)-a(n)| is also a digit of a(n): lexicographic first such sequence with no repeated term.

1, 2, 4, 8, 16, 5, 10, 9, 18, 7, 14, 3, 6, 12, 11, 22, 20, 40, 36, 30, 27, 25, 23, 21, 19, 28, 26, 24, 46, 42, 38, 35, 32, 29, 31, 34, 37, 44, 48, 52, 47, 43, 39, 72, 45, 41, 55, 50, 100, 89, 80, 88, 96, 87, 79, 70, 63, 57, 62, 56, 51, 66, 60, 54, 49, 53, 58, 113, 82, 74, 67, 61, 77, 84, 76, 69, 75, 68, 134, 90, 81

Offset

1,2

Comments

This sequence is a permutation of the positive integers, in contrast to the variant A277858, which was the inspiration for this sequence but which is defined using the much stronger constraint "|a(n+1)-a(n)| is a substring of a(n)".

Links

Table of n, a(n) for n=1..81.

Prog

(PARI) u=[a=1]; for(n=1, 99, print1(a", "); u=setunion(u, [a]); while(#u>2&&u[2]==u[1]+1, u=u[^1]); d=Set(digits(a)); for(k=u[1]+1, 9e9, !setsearch(u, k)&&!#setminus(Set(digits(abs(a-k))), d) &&(a=k)&&break))

Crossrefs

Cf. A277858.

Sequence in context: A261702 A033491 A050076 * A070337 A269305 A225570

Adjacent sequences: A276067 A276068 A276069 * A276071 A276072 A276073

Keyword

nonn,base

Author

M. F. Hasler, Nov 04 2016

Status

approved