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A061878
|First digit - second digit + third digit - fourth digit ...| = 9.
0
9, 90, 108, 119, 207, 218, 229, 306, 317, 328, 339, 405, 416, 427, 438, 449, 504, 515, 526, 537, 548, 559, 603, 614, 625, 636, 647, 658, 669, 702, 713, 724, 735, 746, 757, 768, 779, 801, 812, 823, 834, 845, 856, 867, 878, 889, 900, 911, 922, 933, 944, 955
OFFSET
1,1
COMMENTS
Differs from A061478 at the 59th term.
MATHEMATICA
Do[ a = IntegerDigits[ n ]; l = Length[ a ]; e = o = {}; Do[ o = Append[ o, a[ [ 2k - 1 ] ]], {k, 1, l/2 + .5} ]; Do[ e = Append[ e, a[ [ 2k ] ] ], {k, 1, l/2} ]; If[ Abs[ Apply[ Plus, o ] - Apply[ Plus, e ] ] == 9, Print[ n ] ], {n, 1, 1500} ]
ds9Q[n_]:=Module[{idn=IntegerDigits[n], ker}, ker=Table[(-1)^i, {i, 2, Length[idn]+1}]; First[ListCorrelate[ker, idn]]==9]; Select[Range[1000], ds9Q] (* Harvey P. Dale, Feb 14 2011 *)
KEYWORD
nonn,base,easy
AUTHOR
Robert G. Wilson v, May 10 2001
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), May 15 2001
STATUS
approved