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 A180116 A008619(n-1)-fold concatenation of A109613(n). 1
 1, 3, 33, 55, 555, 777, 7777, 9999, 99999, 1111111111, 111111111111, 131313131313, 13131313131313, 15151515151515, 1515151515151515, 1717171717171717, 171717171717171717, 191919191919191919, 19191919191919191919, 21212121212121212121, 2121212121212121212121 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Written underneath, the first terms have increasing lengths filling a triangular shape: 1, 3, 33, 55, 555, 777, ... LINKS MAPLE cat2 := proc(a, b) a*10^(max(1, 1+ilog10(b)))+b ; end proc: A008619 := proc(n) 1+floor(n/2) ; end proc: A109613 := proc(n) 2*floor(n/2)+1 ; end proc: A180116 := proc(n) a := A109613(n) ; for t from 2 to A008619(n-1) do a := cat2(a, A109613(n)) ; end do: a ; end proc: seq(A180116(n), n=1..24) ; # R. J. Mathar, Sep 19 2010 CROSSREFS Cf. A000217, A109613, A008619. Sequence in context: A084502 A248397 A069165 * A282039 A186680 A139222 Adjacent sequences:  A180113 A180114 A180115 * A180117 A180118 A180119 KEYWORD nonn,base,less AUTHOR Mark Dols, Aug 10 2010 EXTENSIONS Edited by R. J. Mathar, Sep 19 2010 STATUS approved

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Last modified August 7 22:44 EDT 2020. Contains 336279 sequences. (Running on oeis4.)