A066598 Numbers which can be expressed as the product of a number and its reversal in four different ways.

1015560, 1446480, 1854720, 10155600, 14464800, 18547200, 51665040, 59552640, 67944240, 78127560, 82623060, 88560360, 95236960, 99497160, 101556000, 105094080, 108656860, 110937960, 117681480, 118072080, 124942090, 135647680

Offset

1,1

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Mathematica

f[n_] := (m = ToExpression[StringReverse[ToString[n]]]; If[n > m, n*m, 0]); a = Sort[ Table[ f[n], {n, 0, 10^6}]]; While[ a[[1]] == 0, a = Drop[a, 1]]; a[[ Select[ Range[ Length[a]] - 3, a[[ # ]] == a[[ # + 3 ]] & ]]]

Crossrefs

Cf. A066531.

Sequence in context: A210274 A252916 A340435 * A212940 A232144 A293127

Adjacent sequences: A066595 A066596 A066597 * A066599 A066600 A066601

Keyword

nonn

Author

Robert G. Wilson v, Jan 08 2002

Status

approved