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 A038862 Numbers n such that n ends with '7' and is the difference between two positive cubes in at least one way. 1
 7, 37, 117, 127, 217, 387, 397, 547, 657, 817, 1027, 1197, 1267, 1387, 1647, 1657, 1727, 2107, 2437, 2457, 2717, 2977, 3087, 3367, 3997, 4167, 4447, 4697, 4977, 5167, 5677, 5707, 6327, 6347, 6487, 6517, 7057, 7317, 7657, 7957, 8587, 8937, 9197, 9317 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 MAPLE filter:= proc(n) local t, y, r;   for t in sort(convert(numtheory:-divisors(n), list))  do     r:= 12*n*t-3*t^4;     if r < 0 then return false fi;     if not issqr(r) then next fi;     y:= (sqrt(r)-3*t^2)/(6*t);     if y::posint then return true fi   od;   false end proc: select(filter, [seq(i, i=7..10000, 10)]); # Robert Israel, Aug 08 2019 CROSSREFS Cf. A181123. Sequence in context: A159491 A106064 A282001 * A136204 A139891 A082113 Adjacent sequences:  A038859 A038860 A038861 * A038863 A038864 A038865 KEYWORD nonn,base AUTHOR EXTENSIONS Name corrected by Robert Israel, Aug 08 2019 STATUS approved

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Last modified October 19 04:40 EDT 2019. Contains 328211 sequences. (Running on oeis4.)