A061478 -id:A061478 - cp's OEIS frontend

A061479 Smallest number m such that first digit - second digit + third digit - fourth digit ... (of m) = n.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 109, 209, 309, 409, 509, 609, 709, 809, 909, 10909, 20909, 30909, 40909, 50909, 60909, 70909, 80909, 90909, 1090909, 2090909, 3090909, 4090909, 5090909, 6090909, 7090909, 8090909, 9090909, 109090909, 209090909

Offset: 0

Amarnath Murthy, May 05 2001

			a(14) = 509 as 5-0+9 =14 and it is the smallest such number.

Subsequence of A032945.

Cf. A225693, A008593, A060978-A060980, A060982, A061470-A061478, A061870-A061882.

m = 0; Do[ While[ a = IntegerDigits[ m ]; 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} ]; Abs[ Apply[ Plus, o ] - Apply [ Plus, e ] ] != n, m++ ]; Print[ m ], {n, 1, 50} ]

More terms from Robert G. Wilson v, May 10 2001

A061878 |First digit - second digit + third digit - fourth digit ...| = 9.

Original entry on oeis.org

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

Robert G. Wilson v, May 10 2001

Differs from A061478 at the 59th term.

Cf. A008593, A060978-A060980, A060982, A061470-A061479, A061870-A061882.

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 *)

More terms from Larry Reeves (larryr(AT)acm.org), May 15 2001

cp's OEIS Frontend

A061479 Smallest number m such that first digit - second digit + third digit - fourth digit ... (of m) = n.

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