OFFSET
1,1
COMMENTS
LINKS
Shyam Sunder Gupta, Equal Product of Reversible Numbers (EPRN), Exploring the Beauty of Fascinating Numbers, Springer (2025) Ch. 12, 353-365.
EXAMPLE
63540 = 1440 * 411 = 2520 * 252 = 4410 * 144.
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]] - 2, a[[ # ]] == a[[ # + 2 ]] & ]]]
CROSSREFS
KEYWORD
nonn,changed
AUTHOR
Robert G. Wilson v, Jan 08 2002
EXTENSIONS
Definition clarified by M. F. Hasler, Feb 14 2012
Definition corrected by N. J. A. Sloane, Aug 01 2019
STATUS
approved