A107130 Replace each odd digit d of n with (d-1)/2.

0, 0, 2, 1, 4, 2, 6, 3, 8, 4, 0, 0, 2, 1, 4, 2, 6, 3, 8, 4, 20, 20, 22, 21, 24, 22, 26, 23, 28, 24, 10, 10, 12, 11, 14, 12, 16, 13, 18, 14, 40, 40, 42, 41, 44, 42, 46, 43, 48, 44, 20, 20, 22, 21, 24, 22, 26, 23, 28, 24, 60, 60, 62, 61, 64, 62, 66, 63, 68, 64, 30, 30, 32, 31, 34, 32

Offset: 0

Author

Zak Seidov, May 12 2005

Keywords

• nonn
• base
• easy

Comments

Differs from A065423 starting with a(10) = 0, A065423(10) = 10.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..5000

Crossrefs

Cf. A065423.

Programs

Mathematica

a[n_]:=FromDigits[Map[If[Mod[ #, 2]==1, (#-1)/2, # ]&, IntegerDigits[n]]];Table[a[n], {n, 0, 100}]

PARI

a(n)=fromdigits(apply(d->if(d%2,d\2,d),digits(n))) \\ Charles R Greathouse IV, Apr 07 2022

Python

def A107130(n): return int(str(n).translate({49:48,51:49,53:50,55:51,57:52})) # Chai Wah Wu, Apr 07 2022

Extensions

Edited by Charles R Greathouse IV, Aug 03 2010