|
| |
|
|
A127421
|
|
Numbers whose decimal expansion is a concatenation of 2 consecutive increasing numbers.
|
|
5
|
|
|
|
1, 12, 23, 34, 45, 56, 67, 78, 89, 910, 1011, 1112, 1213, 1314, 1415, 1516, 1617, 1718, 1819, 1920, 2021, 2122, 2223, 2324, 2425, 2526, 2627, 2728, 2829, 2930, 3031, 3132, 3233, 3334, 3435, 3536, 3637, 3738, 3839, 3940, 4041, 4142, 4243, 4344, 4445, 4546
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
LINKS
|
Table of n, a(n) for n=1..46.
|
|
|
FORMULA
|
a(n)=n*10^{1+floor[log(n+1)]}+n+1, with n>=0 - Paolo P. Lava, May 09 2008
|
|
|
EXAMPLE
|
a(1) = "0,1" = 1.
a(13)=1213 because 12 and 13 are two consecutive increasing numbers
|
|
|
MAPLE
|
P:=proc(n) local a, i; for i from 0 by 1 to n do a:=i*10^(1+floor(evalf(log10(i+1), 10)))+i+1; print(a); od; end: P(100); - Paolo P. Lava, May 09 2008
|
|
|
CROSSREFS
|
A variant of A001704. Cf. A127421-A127430.
Sequence in context: A072485 A035333 A001704 * A112131 A088997 A049852
Adjacent sequences: A127418 A127419 A127420 * A127422 A127423 A127424
|
|
|
KEYWORD
|
nonn,base,easy
|
|
|
AUTHOR
|
Artur Jasinski, Jan 14 2007
|
|
|
EXTENSIONS
|
More terms from Joshua Zucker, May 15 2007
|
|
|
STATUS
|
approved
|
| |
|
|
