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A033088

Numbers in which all pairs of consecutive digits differ by 2.

1, 2, 3, 4, 5, 6, 7, 8, 9, 13, 20, 24, 31, 35, 42, 46, 53, 57, 64, 68, 75, 79, 86, 97, 131, 135, 202, 242, 246, 313, 353, 357, 420, 424, 464, 468, 531, 535, 575, 579, 642, 646, 686, 753, 757, 797, 864, 868, 975, 979, 1313, 1353, 1357, 2020

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OFFSET

1,2

COMMENTS

If we restrict the maximum number of digits in the number to n, n >= 1, the sequence is finite and the last term is 9797...97 if n is even or 9797..9 if n is odd. - Enrique Navarrete, Dec 01 2017

LINKS

Iain Fox, Table of n, a(n) for n = 1..947

PROG

(PARI) is(n) = for(i=2, #n=digits(n), if(abs(n[i]-n[i-1]) != 2, return(0))); 1 \\ Iain Fox, Dec 01 2017

CROSSREFS

Sequence in context: A165165 A075776 A261556 * A307498 A034294 A304246

Adjacent sequences: A033085 A033086 A033087 * A033089 A033090 A033091

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

URL: https://oeis.org/A033088

⇱ A033088 - OEIS