This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A019519 Concatenate odd numbers. 10
 1, 13, 135, 1357, 13579, 1357911, 135791113, 13579111315, 1357911131517, 135791113151719, 13579111315171921, 1357911131517192123, 135791113151719212325, 13579111315171921232527, 1357911131517192123252729, 135791113151719212325272931 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 REFERENCES X. Chen and M. Le, The Module Periodicity of Smarandache Concatenated Odd Sequence, Smarandache Notions Journal, Vol. 9, No. 1-2. 1998, 103-104. H. Ibstedt, A Few Smarandache Sequences, Smarandache Notions Journal, Vol. 8, No. 1-2-3, 1997, 170-183.. S. Smarandoiu, Convergence of Smarandache continued fractions, Abstract 96T-11-195, Abstracts Amer. Math. Soc., 17 (No. 4, 1996), 680. LINKS F. Smarandache, Definitions, Solved and Unsolved Problems, Conjectures, ... , edited by M. Perez, Xiquan Publishing House 2000 F. Smarandache, Collected Papers, Vol. II, Tempus Publ. Hse., Bucharest, Romania, 1996 Eric Weisstein's World of Mathematics, Consecutive Number Sequences FORMULA Sequence grows like 10^K, where K = 2+floor[log_10 n] + floor[log_10 a(n-1)]. More generally we may consider a(n)= F(a(n-1),n)*B^K + G(a(n-1),n); K = floor[log_B H(a(n-1),n)]; F(a(n-1),n); G(a(n-1),n); H(a(n-1),n) integer polynomials; B integer. - Ctibor O. Zizka, Mar 08 2008 a(n)=a(n-1)*10^[log10(2*n-1)+1]+2*n-1, with a(1)=1. [From Paolo P. Lava, Mar 05 2010] MATHEMATICA nn=20; With[{odds=Range[1, 2nn+1, 2]}, Table[FromDigits[Flatten[ IntegerDigits/@ Take[odds, n]]], {n, nn}]] (* Harvey P. Dale, Aug 14 2014 *) CROSSREFS Primes are in A048847, while their indices are in A046036. Sequence in context: A132930 A130774 A179619 * A243216 A112225 A069511 Adjacent sequences:  A019516 A019517 A019518 * A019520 A019521 A019522 KEYWORD base,nonn,easy AUTHOR R. Muller EXTENSIONS More terms from Erich Friedman. More terms from Harvey P. Dale, Aug 14 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 21 16:25 EDT 2019. Contains 328302 sequences. (Running on oeis4.)