

A033088


Numbers n with property that all pairs of consecutive digits differ by 2.


7



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[i1]) != 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



