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.

Previous Showing 21-27 of 27 results.

A061880 First (leftmost) digit - second digit + third digit - fourth digit .... = 11.

Original entry on oeis.org

209, 308, 319, 407, 418, 429, 506, 517, 528, 539, 605, 616, 627, 638, 649, 704, 715, 726, 737, 748, 759, 803, 814, 825, 836, 847, 858, 869, 902, 913, 924, 935, 946, 957, 968, 979, 2090, 3080, 3091, 3190, 4070, 4081, 4092, 4180, 4191, 4290, 5060, 5071
Offset: 1

Views

Author

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

Keywords

Comments

Note that all entries are divisible by eleven.

Links

Crossrefs

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

Programs

  • Mathematica
    Select[Range[11,6000,11],Total[Times@@@Partition[Riffle[ IntegerDigits[ #],{1,-1},{2,-1,2}],2]]==11&] (* Harvey P. Dale, Jun 21 2014 *)

A061475 First (leftmost) digit - second digit + third digit - fourth digit .... = 6.

Original entry on oeis.org

6, 60, 71, 82, 93, 105, 116, 127, 138, 149, 204, 215, 226, 237, 248, 259, 303, 314, 325, 336, 347, 358, 369, 402, 413, 424, 435, 446, 457, 468, 479, 501, 512, 523, 534, 545, 556, 567, 578, 589, 600, 611, 622, 633, 644, 655, 666, 677, 688, 699, 710, 721, 732
Offset: 1

Views

Author

Amarnath Murthy, May 05 2001

Keywords

Crossrefs

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

Extensions

More terms from Robert G. Wilson v, May 10 2001 and from Larry Reeves (larryr(AT)acm.org), May 14 2001

A061476 First (leftmost) digit - second digit + third digit - fourth digit .... = 7.

Original entry on oeis.org

7, 70, 81, 92, 106, 117, 128, 139, 205, 216, 227, 238, 249, 304, 315, 326, 337, 348, 359, 403, 414, 425, 436, 447, 458, 469, 502, 513, 524, 535, 546, 557, 568, 579, 601, 612, 623, 634, 645, 656, 667, 678, 689, 700, 711, 722, 733, 744, 755, 766, 777, 788
Offset: 1

Views

Author

Amarnath Murthy, May 05 2001

Keywords

Crossrefs

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

Programs

  • Mathematica
    Select[Range[800],Total[Times@@@Partition[Riffle[IntegerDigits[#],{1,-1},{1,-1,2}],2]]==7&] (* Harvey P. Dale, May 01 2022 *)

Extensions

More terms from Robert G. Wilson v, May 10 2001 and from Larry Reeves (larryr(AT)acm.org), May 15 2001

A061871 |First digit - second digit + third digit - fourth digit ...| = 2.

Original entry on oeis.org

2, 13, 20, 24, 31, 35, 42, 46, 53, 57, 64, 68, 75, 79, 86, 97, 101, 112, 123, 130, 134, 141, 145, 152, 156, 163, 167, 174, 178, 185, 189, 196, 200, 211, 222, 233, 240, 244, 251, 255, 262, 266, 273, 277, 284, 288, 295, 299, 310, 321, 332, 343, 350, 354, 361
Offset: 1

Views

Author

Robert G. Wilson v, May 10 2001

Keywords

Crossrefs

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

Programs

  • 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 ] ] == 2, Print[ n ] ], {n, 1, 1000} ]

A061874 |First digit - second digit + third digit - fourth digit ...| = 5.

Original entry on oeis.org

5, 16, 27, 38, 49, 50, 61, 72, 83, 94, 104, 115, 126, 137, 148, 159, 160, 171, 182, 193, 203, 214, 225, 236, 247, 258, 269, 270, 281, 292, 302, 313, 324, 335, 346, 357, 368, 379, 380, 391, 401, 412, 423, 434, 445, 456, 467, 478, 489, 490, 500, 511, 522, 533
Offset: 1

Views

Author

Robert G. Wilson v, May 10 2001

Keywords

Crossrefs

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

Programs

  • 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 ] ] == 5, Print[ n ] ], {n, 1, 1000} ]
Select[Range[600],Abs[Total[Times@@@Partition[Riffle[IntegerDigits[#],{1,-1},{2,-1,2}],2]]]==5&] (* Harvey P. Dale, Dec 15 2012 *)

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

Views

Author

Robert G. Wilson v, May 10 2001

Keywords

Comments

Differs from A061478 at the 59th term.

Crossrefs

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

Programs

  • 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 *)

Extensions

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

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

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

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]
Previous Showing 21-27 of 27 results.

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