A071687 Non-palindromic numbers such that either x=q1.Rev[x] or Rev[x]=q2.x, where R[x]=A004086[x] and q1 or q2 are integers not divisible by 10.

510, 540, 810, 1089, 2100, 2178, 4200, 5200, 5610, 5700, 5940, 6300, 8400, 8712, 8910, 9801, 10989, 21978, 23100, 27000, 46200, 51510, 52200, 52800, 54540, 56610, 57200, 59940, 65340, 69300, 81810, 87912, 89910, 98901, 109989, 212100, 217800

Offset

1,1

Links

Table of n, a(n) for n=1..37.

Formula

q=Max[n/Rev[n], Rev[n]/n]=10m+r integer, where r>0, q>1.

Example

Includes special cases of A071685. Examples represented by {n, Rev[n], integer-quotient} triples: {1089, 9801, 9}, {87912, 21979, 4}, {5610, 165, 34}, {610000, 16, 38125}, etc.

Mathematica

nd[x_, y_] := 10*x+y tn[x_] := Fold[nd, 0, x] ed[x_] := IntegerDigits[x] red[x_] := Reverse[ed[x]] Do[s=Mod[ma=Max[{n, tn[red[n]]}], mi=Min[{n, r=tn[red[n]]}]]; If[Equal[s, 0]&&!Equal[n, r] &&!Equal[Mod[ma/mi, 10], 0], Print[{n, r, Max[r/n, n/r]}]], {n, 1, 1000000}]

Crossrefs

Cf. A071685, A004046, A055483, A069554.

Sequence in context: A126582 A062905 A062914 * A345361 A048254 A303994

Adjacent sequences: A071684 A071685 A071686 * A071688 A071689 A071690

Keyword

base,nonn

Author

Labos Elemer, Jun 03 2002

Status

approved