cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A176892 Decimal representation of the reverted binary representation of n followed by digits substitution 0->2, 1->3.

Original entry on oeis.org

2, 3, 23, 33, 223, 323, 233, 333, 2223, 3223, 2323, 3323, 2233, 3233, 2333, 3333, 22223, 32223, 23223, 33223, 22323, 32323, 23323, 33323, 22233, 32233, 23233, 33233, 22333, 32333, 23333, 33333, 222223, 322223, 232223, 332223, 223223
Offset: 0

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Author

Roger L. Bagula, Apr 28 2010

Keywords

Comments

Revert the digits of A007088(n), preserving zeros, and increase each digit by 2 (add the repunit A002276 with the same number of digits).

Examples

			n=10 is A007088(10)= 1010 in binary, reverted 0101. Adding 2222 generates a(10)=2323.
		

Crossrefs

Programs

  • Haskell
    import Data.List (unfoldr); import Data.Tuple (swap)
    a176892 0 = 2a176892 n = foldl (\v d -> 10 * v + d + 2) 0 $
       unfoldr (\x -> if x == 0 then Nothing else Just $ swap $ divMod x 2) n
    -- Reinhard Zumkeller, Jul 16 2015
  • Mathematica
    Table[Sum[Table[((IntegerDigits[ n, 2]) /. 0 -> 2) /. 1 -> 3, {n, 0, 50}][[n]][[m]]*10^(m - 1),
    {m, 1, Length[Table[((IntegerDigits[n, 2]) /. 0 -> 2) /. 1 -> 3, {n, 0, 50}][[n]]]}], {n, 1, 51}]