

A136414


Put the natural numbers together without spaces and read them two at a time advancing one space each time.


6



12, 23, 34, 45, 56, 67, 78, 89, 91, 10, 1, 11, 11, 12, 21, 13, 31, 14, 41, 15, 51, 16, 61, 17, 71, 18, 81, 19, 92, 20, 2, 21, 12, 22, 22, 23, 32, 24, 42, 25, 52, 26, 62, 27, 72, 28, 82, 29, 93, 30, 3, 31, 13, 32, 23, 33, 33, 34, 43, 35, 53, 36, 63, 37, 73, 38, 83, 39, 94, 40, 4, 41, 14
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OFFSET

1,1


COMMENTS

a(n) = A162711(n,2) for n>1.  Reinhard Zumkeller, Jul 11 2009


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000


FORMULA

a(n) = 10*A007376(n) + A007376(n+1).  Reinhard Zumkeller, Jul 11 2009


EXAMPLE

34 is the third entry because the natural numbers written together look like 1234567891011 and reading them off two at a time produces 12, 23, 34, ...


PROG

(Haskell)
a136414 n = a136414_list !! (n1)
a136414_list = zipWith (+) (tail a007376_list) $ map (10 *) a007376_list
 Reinhard Zumkeller, Jul 28 2011


CROSSREFS

Cf. A001704, A193431, A193492, A193493.
Sequence in context: A088783 A029756 A104340 * A017401 A004960 A098953
Adjacent sequences: A136411 A136412 A136413 * A136415 A136416 A136417


KEYWORD

easy,nonn,base,look


AUTHOR

Ben Paul Thurston, Mar 31 2008


EXTENSIONS

More terms from Reinhard Zumkeller, Jul 11 2009


STATUS

approved



