A107837 Leftmost digit of a(n) represents the number of even digits in a(n); rightmost digit of a(n) represents the number of odd digits in a(n).

20, 112, 132, 152, 172, 192, 201, 221, 241, 261, 281, 1013, 1033, 1053, 1073, 1093, 1103, 1123, 1143, 1163, 1183, 1213, 1233, 1253, 1273, 1293, 1303, 1323, 1343, 1363, 1383, 1413, 1433, 1453, 1473, 1493, 1503, 1523, 1543, 1563, 1583, 1613, 1633, 1653

Offset

1,1

Links

Table of n, a(n) for n=1..44.

Example

20 has two even digits ("2" and "0") and zero odd digit; 112 has one even digit ("2") and two odd digits ("1" and "1"), etc.

Mathematica

okQ[n_]:=Module[{idn=IntegerDigits[n]}, First[idn]== Count[idn, _?EvenQ]&&Last[idn]==Count[idn, _?OddQ]]; Select[Range[2000], okQ]  (* Harvey P. Dale, Mar 13 2011 *)

Crossrefs

Sequence in context: A228243 A086605 A321050 * A267843 A271494 A220928

Adjacent sequences: A107834 A107835 A107836 * A107838 A107839 A107840

Keyword

base,easy,nonn

Author

Eric Angelini, Jun 12 2005

Status

approved