The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A325906 a(n) = ( (-1)^n * Sum_{k=0..n-2} (-1)^k*10^(2^k) + 10^(2^(n-1)) - ((-1)^n+3)/2 )/9. 3
 1, 12, 1121, 11112212, 1111111122221121, 11111111111111112222222211112212, 1111111111111111111111111111111122222222222222221111111122221121 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Seiichi Manyama, Table of n, a(n) for n = 1..10 EXAMPLE n | a(n) | A325910(n) --+------------------+----------------- 1 | 1 | 1 2 | 12 | 10 3 | 1121 | 1101 4 | 11112212 | 11110010 5 | 1111111122221121 | 1111111100001101 MATHEMATICA a[n_] := ((-1)^n * Sum[(-1)^k * 10^(2^k), {k, 0, n - 2}] + 10^(2^(n - 1)) - ((-1)^n + 3)/2)/9; Array[a, 7] (* Amiram Eldar, May 07 2021 *) PROG (PARI) {a(n) = ((-1)^n*sum(k=0, n-2, (-1)^k*10^2^k)+10^2^(n-1)-((-1)^n+3)/2)/9} CROSSREFS Cf. A325907, A325910. Sequence in context: A354822 A260030 A160010 * A181718 A004073 A109229 Adjacent sequences: A325903 A325904 A325905 * A325907 A325908 A325909 KEYWORD nonn AUTHOR Seiichi Manyama, Sep 08 2019 STATUS approved

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

Last modified August 5 17:52 EDT 2024. Contains 374954 sequences. (Running on oeis4.)