A061882 a(n) = Smallest nontrivial number k > 9 such that first (leftmost) digit - second digit + third digit - fourth digit ... of k = n.

11, 10, 20, 30, 40, 50, 60, 70, 80, 90, 109, 209, 309, 409, 509, 609, 709, 809, 909, 10909, 20909, 30909, 40909, 50909, 60909, 70909, 80909, 90909, 1090909, 2090909, 3090909, 4090909, 5090909, 6090909, 7090909, 8090909, 9090909, 109090909

Offset: 0

Author

Larry Reeves (larryr(AT)acm.org), May 15 2001

Keywords

• base
• nonn
• easy

Comments

Starting with 109, this sequence has the same terms as A060982 and A061479. - Georg Fischer, May 24 2022

Crossrefs

Cf. A008593, A051885, A060978-A060980, A060982, A061470-A061479, A061870-A061882.

Programs

PARI

a(n) = my(k=1,d=digits(k)); while (sum(k=1, #d, (-1)^(k+1)*d[k]) != n, k++; d=digits(k)); k; \\ Michel Marcus, May 24 2022

Extensions

Definition amended by Georg Fischer, May 24 2022