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 A137465 1 concatenated with n n's concatenated with 1. 0
 111, 1221, 13331, 144441, 1555551, 16666661, 177777771, 1888888881, 19999999991, 1101010101010101010101, 111111111111111111111111, 11212121212121212121212121, 1131313131313131313131313131, 114141414141414141414141414141, 11515151515151515151515151515151 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA a(n) = 10^(1 + n*(1+floor(log(n)))) + 10*Sum_{k=0..n-1} (n + 10^(1+floor(log(n)))*k) + 1, with n >= 1. - Paolo P. Lava, May 08 2008 EXAMPLE a(7) = 177777771. MAPLE P:=proc(n) local a, i, k; for i from 1 by 1 to n do a:=10^(1+i*(1+floor(evalf(log10(i), 10))))+10*sum(i*10^((1+floor(evalf(log10(i), 10)))*k), 'k'=0..(i-1))+1; print(a); od; end: P(30); # Paolo P. Lava, May 08 2008 MATHEMATICA Table[FromDigits[Join[{1}, Flatten[IntegerDigits/@Table[n, {n}]], {1}]], {n, 15}] (* Harvey P. Dale, Apr 19 2013 *) CROSSREFS Cf. A000461 (concatenate n n times). Sequence in context: A102782 A302475 A303256 * A101152 A250145 A075859 Adjacent sequences: A137462 A137463 A137464 * A137466 A137467 A137468 KEYWORD easy,nonn,base AUTHOR Ctibor O. Zizka, Apr 19 2008 EXTENSIONS More terms from Harvey P. Dale, Apr 19 2013 STATUS approved

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Last modified March 20 22:57 EDT 2023. Contains 361392 sequences. (Running on oeis4.)