A252490 Numbers whose set of digits is simply connected, with 9 and 0 considered as neighbors.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 21, 22, 23, 32, 33, 34, 43, 44, 45, 54, 55, 56, 65, 66, 67, 76, 77, 78, 87, 88, 89, 90, 98, 99, 100, 101, 102, 109, 110, 111, 112, 120, 121, 122, 123, 132, 190, 201, 210, 211, 212, 213, 221, 222, 223, 231, 232, 233, 234, 243, 312, 321, 322, 323, 324, 332, 333, 334, 342, 343, 344, 345, 354, 423, 432

Offset

1,2

Comments

The set of digits must consist of a single run without "holes", but for a cyclic topology where 9 and 0 are seen as neighbors.

A superset of A134336. Namely, numbers in A134336 or such that the complement of their digits in {0,...,9} satisfies the criterion of A134336.

Links

Danny Rorabaugh, Table of n, a(n) for n = 1..10000

Prog

(PARI) is(n)=vecmax(if((d=Set(digits(n)))[1], d, d=setminus(vector(9, i, i), d)))-vecmin(d)==#d-1

Crossrefs

Cf. A032981, A050278, A033075 (a subsequence), A010785, A108965, A134336 (a subsequence).

Sequence in context: A261370 A257737 A130577 * A178403 A134336 A131207

Adjacent sequences: A252487 A252488 A252489 * A252491 A252492 A252493

Keyword

nonn,base,easy

Author

M. F. Hasler, Dec 24 2014

Status

approved