|
|
A033088
|
|
Numbers in which all pairs of consecutive digits differ by 2.
|
|
8
|
|
|
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
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
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
|
|
|
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
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|