A061881 First (leftmost) digit - second digit + third digit - fourth digit .... = 12.

309, 408, 419, 507, 518, 529, 606, 617, 628, 639, 705, 716, 727, 738, 749, 804, 815, 826, 837, 848, 859, 903, 914, 925, 936, 947, 958, 969, 3090, 4080, 4091, 4190, 5070, 5081, 5092, 5180, 5191, 5290, 6060, 6071, 6082, 6093, 6170, 6181, 6192, 6280, 6291

Offset

1,1

Links

Table of n, a(n) for n=1..47.

Mathematica

okQ[n_]:=Plus@@(Times@@#&/@Partition[Most[Riffle[IntegerDigits[10n], {1, -1}]], 2])==12; Select[Range[7000], okQ]  (* Harvey P. Dale, Jan 17 2011 *)
okQ[n_] := Module[{d = IntegerDigits[n]}, Plus @@ Take[d, {1, Length[d], 2}] - Plus @@ Take[d, {2, Length[d], 2}] == 12]; Select[Range[7000], okQ]

Crossrefs

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

Sequence in context: A159004 A031782 A060980 * A121322 A067730 A183627

Adjacent sequences: A061878 A061879 A061880 * A061882 A061883 A061884

Keyword

base,nonn,easy

Author

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

Status

approved