cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

Original entry on oeis.org

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

Views

Author

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

Keywords

Crossrefs

Programs

  • 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]