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A193492
Put the natural numbers together without spaces and read them four at a time advancing one space each time.
4
1234, 2345, 3456, 4567, 5678, 6789, 7891, 8910, 9101, 1011, 111, 1112, 1121, 1213, 2131, 1314, 3141, 1415, 4151, 1516, 5161, 1617, 6171, 1718, 7181, 1819, 8192, 1920, 9202, 2021, 212, 2122, 1222, 2223, 2232, 2324, 3242, 2425, 4252, 2526, 5262, 2627, 6272
OFFSET
1,1
LINKS
FORMULA
a(n) = 10*(10*(10*A007376(n)+A007376(n+1))+A007376(n+2))+A007376(n+3).
MATHEMATICA
FromDigits/@Partition[Flatten[IntegerDigits/@Range[30]], 4, 1] (* Harvey P. Dale, Aug 19 2012 *)
PROG
(Haskell)
a193492 n = a193492_list !! (n-1)
a193492_list = f a007376_list where
f xs'@(x:xs) = ((foldl (\u v -> 10*u + v) 0) $ take 4 xs') : f xs
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Jul 28 2011
STATUS
approved