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A109880
Numbers n such that n and its digit reversal both are difference of successive cubes.
1
1, 7, 19, 91, 127, 721, 919, 14491, 19441, 113491, 177877, 194311, 778771, 1081801, 1188811, 1767169, 1927207, 1946491, 7027291, 9617671, 16056847, 74775169, 74865061, 96157747, 129869461, 164968921, 167828761, 180676081, 189202267, 757333297, 762202981, 792333757, 1917766117, 7116677191
OFFSET
1,2
COMMENTS
A subsequence of A109879.
EXAMPLE
19 = 3^3-2^3 and 91 = 6^3-5^3.
MATHEMATICA
okQ[x_]:=Module[{revx=FromDigits[Reverse[IntegerDigits[x]]]}, And@@(And@@IntegerQ/@(n/.Solve[1+3n+3n^2==x, n])&&And@@IntegerQ/@(n/.Solve[1+3n+3n^2==revx, n]))] Select[Range[90000], okQ] - Harvey P. Dale, Aug 06 2007
CROSSREFS
Cf. A109879.
Sequence in context: A267378 A088988 A109879 * A363668 A245489 A084603
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Jul 10 2005
EXTENSIONS
More terms from Harvey P. Dale, Aug 06 2007
23 more terms from Donovan Johnson, Feb 21 2008
STATUS
approved