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.

User: Larry Reeves

Larry Reeves's wiki page.

Larry Reeves has authored 74 sequences. Here are the ten most recent ones:

A057926 a(0) = 1, a(1) = 3, a(n) = smallest number such that sequence b(n) = a(n) OR a(n+1) is strictly monotonically increasing.

Original entry on oeis.org

1, 3, 4, 8, 5, 10, 16, 11, 20, 32, 21, 34, 24, 35, 28, 64, 29, 66, 32, 67, 36, 72, 37, 74, 48, 75, 52, 128, 53, 130, 56, 131, 60, 192, 61, 194, 256, 195, 260, 200, 261, 202, 272, 203, 276, 224, 277, 226, 280, 227, 284, 512, 285, 514, 288, 515, 292, 520, 293, 522, 304
Offset: 0

Views

Author

Larry Reeves (larryr(AT)acm.org), Oct 03 2000

Keywords

Examples

			See example in A051145.

Crossrefs

Cf. A051145, A057927, A057928.

A057927 Sequence b(n) mentioned in A057926.

Original entry on oeis.org

3, 7, 12, 13, 15, 26, 27, 31, 52, 53, 55, 58, 59, 63, 92, 93, 95, 98, 99, 103, 108, 109, 111, 122, 123, 127, 180, 181, 183, 186, 187, 191, 252, 253, 255, 450, 451, 455, 460, 461, 463, 474, 475, 479, 500, 501, 503, 506, 507, 511, 796, 797, 799, 802, 803, 807
Offset: 1

Views

Author

Larry Reeves (larryr(AT)acm.org), Oct 03 2000

Keywords

Crossrefs

Cf. A057926, A057928.

A057929 a(0)=2, a(1)=5, a(n) = smallest number such that sequence b(n) = a(n) OR a(n+1) is strictly monotonically increasing.

Original entry on oeis.org

2, 5, 8, 6, 9, 16, 10, 17, 12, 18, 13, 32, 14, 33, 16, 34, 17, 36, 18, 37, 24, 38, 25, 64, 26, 65, 28, 66, 29, 96, 30, 97, 128, 98, 129, 100, 130, 101, 136, 102, 137, 112, 138, 113, 140, 114, 141, 256, 142, 257, 144, 258, 145, 260, 146, 261, 152, 262, 153, 288, 154
Offset: 0

Views

Author

Larry Reeves (larryr(AT)acm.org), Oct 03 2000

Keywords

Examples

			See example in A051145

Crossrefs

Cf. A051145, A057930, A057931.

A057930 Sequence b(n) mentioned in A057929.

Original entry on oeis.org

7, 13, 14, 15, 25, 26, 27, 29, 30, 31, 45, 46, 47, 49, 50, 51, 53, 54, 55, 61, 62, 63, 89, 90, 91, 93, 94, 95, 125, 126, 127, 225, 226, 227, 229, 230, 231, 237, 238, 239, 249, 250, 251, 253, 254, 255, 397, 398, 399, 401, 402, 403, 405, 406, 407, 413, 414, 415
Offset: 1

Views

Author

Larry Reeves (larryr(AT)acm.org), Oct 03 2000

Keywords

Crossrefs

Cf. A057929, A057931.

A061533 Limiting sequence of digits in A061584, starting with least significant digit.

Original entry on oeis.org

6, 3, 8, 1, 8, 4, 6, 8, 4, 4, 2, 6, 3, 8, 4, 4, 2, 4, 2, 2, 1, 6, 3, 8, 1, 8, 4, 4, 2, 4, 2, 2, 1, 4, 2, 2, 1, 2, 1, 6, 6, 3, 8, 1, 8, 4, 6, 8, 4, 4, 2, 4, 2, 2, 1, 4, 2, 2, 1, 2, 1, 6, 4, 2, 2, 1, 2, 1, 6, 2, 1, 6, 6, 3, 6, 3, 8, 1, 8, 4, 6, 8, 4, 4, 2, 6, 3, 8, 4, 4, 2, 4, 2, 2, 1, 4, 2, 2, 1, 2, 1, 6, 4, 2
Offset: 1

Views

Author

Larry Reeves (larryr(AT)acm.org), May 16 2001

Keywords

Crossrefs

Cf. A061584.

A057439 Values of S from sequence A007773.

Original entry on oeis.org

0, 1, 14, 38, 44, 46, 84, 86, 90, 94, 96, 100, 104, 106, 154, 156, 160, 162, 164, 166, 170, 172, 174, 176, 178, 180, 182, 184, 188, 190, 192, 196, 198, 200, 202, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282, 284, 286, 288, 290, 292, 294
Offset: 1

Views

Author

Larry Reeves (larryr(AT)acm.org), Sep 08 2000

Keywords

Examples

			A007773(4)= 3: 0,2,1,3 -> 38; 0,1,2,3 -> 44; 0,1,3,2 ->46

Crossrefs

Cf. A007773.

Extensions

More terms from Naohiro Nomoto, Oct 29 2001

A061868 Numbers n such that n^2 has property that the sum of its digits and the product of its digits are squares (allowing zeros).

Original entry on oeis.org

0, 1, 2, 3, 10, 12, 20, 21, 30, 45, 48, 51, 60, 90, 95, 100, 101, 102, 103, 104, 105, 110, 120, 122, 130, 140, 148, 150, 175, 176, 180, 200, 201, 202, 203, 210, 212, 220, 221, 230, 247, 248, 249, 257, 265, 266, 274, 283, 284, 300, 301, 302, 310, 318, 319, 321
Offset: 1

Views

Author

Larry Reeves (larryr(AT)acm.org), May 11 2001

Keywords

Links

Crossrefs

A061268 does not allow zero product of digits.

Programs

  • Mathematica
    spsQ[n_]:=Module[{idn2=IntegerDigits[n^2]},IntegerQ[Sqrt[Total[idn2]]] && IntegerQ[ Sqrt[Times@@idn2]]]; Select[Range[0,350],spsQ] (* Harvey P. Dale, Dec 12 2013 *)

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 *)

A061867 Squares whose product of digits is also a square (allowing zeros).

Original entry on oeis.org

0, 1, 4, 9, 49, 100, 144, 289, 400, 441, 900, 1024, 1089, 1444, 1600, 2025, 2209, 2304, 2401, 2500, 2601, 2704, 2809, 3025, 3600, 4096, 4900, 5041, 6084, 6400, 7056, 7744, 8100, 9025, 9409, 9604, 9801, 10000, 10201, 10404, 10609, 10816, 11025, 11236
Offset: 1

Views

Author

Larry Reeves (larryr(AT)acm.org), May 11 2001

Keywords

References

  • Felice Russo, A set of new Smarandache Functions, Sequences and conjectures in number theory, pp-64, American Research Press, Lupton USA.
  • Amarnath Murthy, Exploring some new ideas on Smarandache Type Sets, Functions and sequences, Vol. 11, No. 1-2-3, Spring 2000.
  • Amarnath Murthy, On the infinitude of Smarandache multiplicative square sequence, (to be published in Smarandache Notions Journal).

Crossrefs

Sequence A053059 removes the numbers with zeros.

Programs

  • Mathematica
    Select[Range[0,200]^2,IntegerQ[Sqrt[Times@@IntegerDigits[#]]]&] (* Harvey P. Dale, Oct 03 2014 *)
  • PARI
    isok(n) = {if (! issquare(n), return (0)); digs = digits(n, 10); issquare(prod(i=1, #digs, digs[i]));}  \\ Michel Marcus, Aug 02 2013

Formula

a(n) ~ n^2. - Charles R Greathouse IV, Sep 19 2012

A057925 Position of first occurrence of 2^n in A057923.

Original entry on oeis.org

2, 1, 3, 6, 9, 15, 27, 36, 51, 87, 135, 243, 315, 531, 735, 969, 1707, 2679, 3831, 6363, 9663, 14559, 23091, 33045, 45999, 77523, 120471, 177639, 252717, 405321, 554037, 795831, 1335087, 1819527, 2491233, 4183467, 5920215, 8051991, 12530967
Offset: 0

Views

Author

Larry Reeves (larryr(AT)acm.org), Oct 03 2000

Keywords

Crossrefs

Cf. A057923, A057924.

Extensions

More terms from David W. Wilson, Jan 11 2001
Definition corrected by Michel Marcus, Aug 02 2013

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.