A071242 Arithmetic mean of n and R(n) where n is a number such that the least significant digit and the most significant digits are of same parity and R(n) is its digit reversal (A004086).

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 11, 22, 33, 44, 55, 22, 33, 44, 55, 66, 22, 33, 44, 55, 66, 33, 44, 55, 66, 77, 33, 44, 55, 66, 77, 44, 55, 66, 77, 88, 44, 55, 66, 77, 88, 55, 66, 77, 88, 99, 101, 202, 303, 404, 505, 111, 212, 313, 414, 515, 121

Offset

0,3

Links

Table of n, a(n) for n=0..65.

Formula

{n + R(n)}/2 for all n which yield integers.

Maple

reversal := proc(n) local i, len, new, temp: new := 0: temp := n: len := floor(log[10](n+.1))+1: for i from 1 to len do new := new+irem(temp, 10)*10^(len-i): temp := floor(temp/10): od: RETURN(new): end: for n from 0 to 500 do if type((n+reversal(n))/2, integer) then printf(`%d, `, (n+reversal(n))/2) fi: od: # James A. Sellers, May 28 2002

Crossrefs

Cf. A071240, A071241.

Sequence in context: A080716 A166461 A275772 * A044959 A353181 A306273

Adjacent sequences: A071239 A071240 A071241 * A071243 A071244 A071245

Keyword

base,nonn

Author

Amarnath Murthy, May 20 2002

Extensions

More terms from James A. Sellers, May 28 2002

Status

approved