A109879 Numbers n such that n and its digit reversal R(n) both are difference of positive cubes.
7, 19, 91, 127, 721, 919, 999, 1385, 1727, 3159, 4376, 5409, 5831, 6734, 7271, 9045, 9513, 10647, 11824, 12691, 14491, 15967, 16939, 19441, 19621, 25352, 26973, 27872, 28737, 29783, 31213, 35163, 35929, 36153, 37962, 37973, 38656, 38792, 39636
Offset: 1
Examples
19 = 3^3 - 2^3 and 91 = 6^3 - 5^3.
Crossrefs
Cf. A109880.
Programs
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Mathematica
t1 = Select[ Union[ Flatten[ Table[n^3 - m^3, {n, 185}, {m, 0, n - 1}]]], # < 10^5 && Mod[ #, 10] != 0 &]; t2 = FromDigits /@ Reverse /@ IntegerDigits /@ t1; Take[ Intersection[t1, t2], 40] (* Robert G. Wilson v, Jul 14 2005 *)
Extensions
Edited and extended by Robert G. Wilson v, Jul 14 2005
Comments