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.

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A190436 a(n) = [(b*n+c)*r] - b*[n*r] - [c*r], where (r,b,c)=(golden ratio,3,2) and []=floor.

Original entry on oeis.org

2, 0, 2, 1, 0, 2, 1, 3, 1, 0, 2, 1, 0, 2, 1, 2, 1, 0, 2, 1, 3, 2, 0, 2, 1, 0, 2, 1, 3, 1, 0, 2, 1, 0, 2, 0, 2, 1, 0, 2, 1, 3, 1, 0, 2, 1, 0, 2, 1, 2, 1, 0, 2, 1, 3, 2, 0, 2, 1, 0, 2, 1, 3, 1, 0, 2, 1, 0, 2, 1, 2, 1, 0, 2, 1, 3, 2, 0, 2, 1, 0, 2, 1, 2, 1, 0, 2, 1, 0, 2, 0, 2, 1, 0, 2, 1, 3, 1, 0, 2, 1, 0, 2, 1, 2, 1, 0, 2, 1, 3, 2, 0, 2, 1, 0
Offset: 1

Views

Author

Clark Kimberling, May 10 2011

Keywords

Comments

Write a(n)=[(bn+c)r]-b[nr]-[cr]. If r>0 and b and c are integers satisfying b>=2 and 0<=c<=b-1, then 0<=a(n)<=b. The positions of 0 in the sequence a are of interest, as are the position sequences for 1,2,...,b. These b+1 position sequences comprise a partition of the positive integers.
Examples:
(golden ratio,2,0): A078588, A005653, A005652
(golden ratio,2,1): A190427 - A190430
(golden ratio,3,0): A140397 - A190400
(golden ratio,3,1): A140431 - A190435
(golden ratio,3,2): A140436 - A190439
(golden ratio,4,c): A140440 - A190461

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio; b = 3; c = 2;
    f[n_] := Floor[(b*n + c)*r] - b*Floor[n*r] - Floor[c*r];
    t = Table[f[n], {n, 1, 320}]
    Flatten[Position[t, 0]] (* A190437 *)
    Flatten[Position[t, 1]] (* A190438 *)
    Flatten[Position[t, 2]] (* A190439 *)
    Flatten[Position[t, 3]] (* A302253 *)

A190445 [(bn+c)r]-b[nr]-[cr], where (r,b,c)=(golden ratio,4,1) and []=floor.

Original entry on oeis.org

3, 1, 4, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 1, 4, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 4, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 4, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 3, 1, 4, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 1, 4, 2, 1, 3, 2, 0
Offset: 1

Views

Author

Clark Kimberling, May 10 2011

Keywords

Comments

Write a(n)=[(bn+c)r]-b[nr]-[cr]. If r>0 and b and c are integers satisfying b>=2 and 0<=c<=b-1, then 0<=a(n)<=b. The positions of 0 in the sequence a are of interest, as are the position sequences for 1,2,...,b. These b+1 position sequences comprise a partition of the positive integers.
Examples:
(golden ratio,2,0): A078588, A005653, A005652
(golden ratio,2,1): A190427-A190430
(golden ratio,3,0): A140397-A190400
(golden ratio,3,1): A140431-A190435
(golden ratio,3,2): A140436-A190439
(golden ratio,4,c): A190440-A190461

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio; b = 4; c = 1;
    f[n_] := Floor[(b*n + c)*r] - b*Floor[n*r] - Floor[c*r];
    t = Table[f[n], {n, 1, 320}]
    Flatten[Position[t, 0]]
    Flatten[Position[t, 1]]
    Flatten[Position[t, 2]]
    Flatten[Position[t, 3]]
    Flatten[Position[t, 4]]

A190457 a(n) = [(bn+c)r]-b[nr]-[cr], where (r,b,c)=(golden ratio,4,3) and []=floor.

Original entry on oeis.org

3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 4, 2, 0, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 4, 2, 1, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 4, 2, 0, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 4, 2, 1, 3, 2, 4, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 4, 2, 1, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 4, 2, 1, 3, 2, 4, 3, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 4, 3
Offset: 1

Views

Author

Clark Kimberling, May 10 2011

Keywords

Comments

Write a(n)=[(bn+c)r]-b[nr]-[cr]. If r>0 and b and c are integers satisfying b>=2 and 0<=c<=b-1, then 0<=a(n)<=b. The positions of 0 in the sequence a are of interest, as are the position sequences for 1,2,...,b. These b+1 position sequences comprise a partition of the positive integers.
Examples:
(golden ratio,2,0): A078588, A005653, A005652
(golden ratio,2,1): A190427-A190430
(golden ratio,3,0): A140397-A190400
(golden ratio,3,1): A140431-A190435
(golden ratio,3,2): A140436-A190439
(golden ratio,4,c): A190440-A190461

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio; b = 4; c = 3;
    f[n_] := Floor[(b*n + c)*r] - b*Floor[n*r] - Floor[c*r];
    t = Table[f[n], {n, 1, 320}]
    Flatten[Position[t, 0]]
    Flatten[Position[t, 1]]
    Flatten[Position[t, 2]]
    Flatten[Position[t, 3]]
    Flatten[Position[t, 4]]

A191331 Positions of 2 in A191329.

Original entry on oeis.org

2, 6, 12, 16, 18, 22, 28, 32, 34, 38, 42, 44, 48, 54, 58, 60, 64, 70, 74, 80, 84, 86, 90, 96, 100, 102, 106, 110, 112, 116, 122, 126, 128, 132, 138, 142, 148, 152, 154, 158, 164, 168, 170, 174, 180, 184, 190, 194, 196, 200, 206, 210, 212, 216, 220, 222, 226, 232, 236, 238, 242, 248, 252, 258, 262, 264, 268, 274, 278, 280, 284, 288
Offset: 1

Views

Author

Clark Kimberling, May 31 2011

Keywords

Comments

Examples

			A191329=(1,2,1,0,1,2,1,0,1,0,1,2,...), so that
a(1)=2, a(2)=6, a(3)=12,...
		

Crossrefs

Programs

A302253 Positions of 3 in A190436.

Original entry on oeis.org

8, 21, 29, 42, 55, 63, 76, 97, 110, 118, 131, 144, 152, 165, 186, 199, 207, 220, 241, 254, 262, 275, 288, 296, 309, 330, 343, 351, 364, 377, 385, 398, 406, 419, 432, 440, 453, 474, 487, 495, 508, 521, 529, 542, 563, 576, 584, 597, 618, 631, 639, 652, 665, 673, 686, 707, 720, 728
Offset: 1

Views

Author

G. C. Greubel, Apr 04 2018

Keywords

Comments

Write a(n) = [(bn+c)r] - b[nr] - [cr]. If r>0 and b and c are integers satisfying b >= 2 and 0 <= c <= b-1, then 0 <= a(n) <= b. The positions of 0 in the sequence a are of interest, as are the position sequences for 1,2,...,b. These b+1 position sequences comprise a partition of the positive integers.
Examples:
(golden ratio,2,0): A078588, A005653, A005652
(golden ratio,2,1): A190427-A190430
(golden ratio,3,0): A140397-A190400
(golden ratio,3,1): A140431-A190435
(golden ratio,3,2): A140436-A190439
(golden ratio,4,c): A140440-A190461

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio; b = 3; c = 2;
    f[n_] := Floor[(b*n + c)*r] - b*Floor[n*r] - Floor[c*r];
    t = Table[f[n], {n, 1, 500}] (* A190436 *)
    Flatten[Position[t, 0]] (* A190437 *)
    Flatten[Position[t, 1]] (* A190438 *)
    Flatten[Position[t, 2]] (* A190439 *)
    Flatten[Position[t, 3]] (* A302253 *)

A190451 [(bn+c)r]-b[nr]-[cr], where (r,b,c)=(golden ratio,4,2) and []=floor.

Original entry on oeis.org

2, 1, 3, 2, 0, 3, 1, 4, 2, 0, 3, 1, 0, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 2, 1, 3, 2, 0, 3, 1, 0, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 1, 0, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 3, 1, 3, 2, 0, 3, 1, 0, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 2, 1, 3, 2, 0, 3, 1, 0, 2, 1, 3, 2, 0, 3, 1, 4, 2, 0, 3, 1, 0, 2, 1, 3, 2, 0, 3, 1, 4, 2, 1, 3, 2, 0, 3, 1, 3, 2, 0, 3, 1, 0
Offset: 1

Views

Author

Clark Kimberling, May 10 2011

Keywords

Comments

Write a(n)=[(bn+c)r]-b[nr]-[cr]. If r>0 and b and c are integers satisfying b>=2 and 0<=c<=b-1, then 0<=a(n)<=b. The positions of 0 in the sequence a are of interest, as are the position sequences for 1,2,...,b. These b+1 position sequences comprise a partition of the positive integers.
Examples:
(golden ratio,2,0): A078588, A005653, A005652
(golden ratio,2,1): A190427-A190430
(golden ratio,3,0): A140397-A190400
(golden ratio,3,1): A140431-A190435
(golden ratio,3,2): A140436-A190439

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio; b = 4; c = 2;
    f[n_] := Floor[(b*n + c)*r] - b*Floor[n*r] - Floor[c*r];
    t = Table[f[n], {n, 1, 320}]
    Flatten[Position[t, 0]]
    Flatten[Position[t, 1]]
    Flatten[Position[t, 2]]
    Flatten[Position[t, 3]]
    Flatten[Position[t, 4]]

A156353 A symmetrical powers triangle sequence: t(n,m) = (m^(n - m) + (n - m)^m).

Original entry on oeis.org

2, 3, 3, 4, 8, 4, 5, 17, 17, 5, 6, 32, 54, 32, 6, 7, 57, 145, 145, 57, 7, 8, 100, 368, 512, 368, 100, 8, 9, 177, 945, 1649, 1649, 945, 177, 9, 10, 320, 2530, 5392, 6250, 5392, 2530, 320, 10, 11, 593, 7073, 18785, 23401, 23401, 18785, 7073, 593, 11, 12, 1124, 20412
Offset: 1

Views

Author

Roger L. Bagula, Feb 08 2009

Keywords

Comments

Equivalently, table by antidiagonals of n^m + m^n for n,m > 0.
Row sums are:
{2, 6, 16, 44, 130, 418, 1464, 5560, 22754, 99726, 465536,...}.

Examples

			{2},
{3, 3},
{4, 8, 4},
{5, 17, 17, 5},
{6, 32, 54, 32, 6},
{7, 57, 145, 145, 57, 7},
{8, 100, 368, 512, 368, 100, 8},
{9, 177, 945, 1649, 1649, 945, 177, 9},
{10, 320, 2530, 5392, 6250, 5392, 2530, 320, 10},
{11, 593, 7073, 18785, 23401, 23401, 18785, 7073, 593, 11},
{12, 1124, 20412, 69632, 94932, 93312, 94932, 69632, 20412, 1124, 12}
		

Crossrefs

Cf. A005652 is the same table with row 0 and column 0 included.

Programs

  • Mathematica
    Clear[t, n, m];
    t[n_, m_] = (m^(n - m) + (n - m)^m);
    Table[Table[t[n, m], {m, 1, n - 1}], {n, 2, 12}];
    Flatten[%]
  • Python
    t=int((math.sqrt(8*n-7) - 1)/ 2)
    m=((t*t+3*t+4)/2-n)**(n-t*(t+1)/2)+(n-t*(t+1)/2)**((t*t+3*t+4)/2-n)
    # Boris Putievskiy, Dec 14 2012

Formula

t(n,m) = (m^(n - m) + (n - m)^m).
a(n) = A004736(n)^A002260(n) + A002260(n)^A004736(n) or
((t*t+3*t+4)/2-n)^(n-(t*(t+1)/2))+ (n-(t*(t+1)/2))^((t*t+3*t+4)/2-n), where t=floor((-1+sqrt(8*n-7))/2). - Boris Putievskiy, Dec 14 2012

Extensions

Edited by Franklin T. Adams-Watters, Oct 26 2009

A203988 a(1)=1 and, for n>1, a(n) is the smallest positive integer greater than a(n-1) such that a(n)+a(k) is not a square for k=1,2,...,n-1.

Original entry on oeis.org

1, 2, 4, 6, 9, 11, 13, 17, 18, 20, 22, 26, 28, 33, 37, 39, 41, 49, 50, 52, 54, 56, 57, 66, 73, 76, 81, 85, 86, 97, 100, 102, 106, 109, 114, 121, 129, 134, 137, 145, 148, 153, 161, 162, 164, 166, 172, 177, 181, 182, 191, 193, 196, 198, 201, 211, 220, 225, 226
Offset: 1

Views

Author

John W. Layman, Jan 09 2012

Keywords

Comments

See A005652 for the case where the sum of two terms is never a Fibonacci number.

Crossrefs

Cf. A005652.

Programs

  • Mathematica
    t = {1}; Do[k = t[[-1]] + 1; While[Length[Select[t, ! IntegerQ[Sqrt[# + k]] &]] < Length[t], k++]; AppendTo[t, k], {n, 2, 100}]; t (* T. D. Noe, Jan 10 2012 *)
  • PARI
    seq(n)={my(a=vector(n)); a[1]=1; for(n=2, n, my(m=a[n-1], f=1); while(f, m++; f=0; for(k=1, n-1, f=issquare(a[k]+m); if(f, break))); a[n]=m); a} \\ Andrew Howroyd, Sep 19 2020

A279934 Positive integers k such that {(k-1)*r} > 1/2, where r = golden ratio = (1 + sqrt(5))/2 and { } = fractional part.

Original entry on oeis.org

2, 4, 7, 9, 10, 12, 15, 17, 18, 20, 22, 23, 25, 28, 30, 31, 33, 36, 38, 41, 43, 44, 46, 49, 51, 52, 54, 56, 57, 59, 62, 64, 65, 67, 70, 72, 75, 77, 78, 80, 83, 85, 86, 88, 91, 93, 96, 98, 99, 101, 104, 106, 107, 109, 111, 112, 114, 117, 119, 120
Offset: 1

Views

Author

Clark Kimberling, Dec 23 2016

Keywords

Crossrefs

Cf. A005652, A279933 (complement).

Programs

  • Mathematica
    r = GoldenRatio;
    t = Table[If[FractionalPart[n r - r] < 1/2, 0, 1 ], {n, 1, 120}] (* {A078588(n-1)} *)
    Flatten[Position[t, 0]]  (* A279933 *)
    Flatten[Position[t, 1]]  (* A279934 *)

Formula

a(n) = 1 + A005652(n).

Extensions

New name from Jianing Song, Sep 12 2019

A140401 Let S be the set of numbers formed from the sum of three distinct elements of A140398, or the sum of three distinct elements of A140399, or the sum of three distinct elements of A140400; sequence gives complement of S.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 18, 21, 23, 26, 29, 31, 34, 39, 42, 47, 55, 60, 68, 76, 81, 89, 102, 110, 123, 144, 157, 178, 199, 212, 233, 267, 288, 322, 377, 411, 466, 521, 555, 610, 699, 754, 843, 987
Offset: 1

Views

Author

Fred Lunnon, Jun 20 2008

Keywords

Crossrefs

Formula

It appears that this consists of the following numbers: { F_{k}, F_{k} + F_{k-3}, F_{k} + F_{k-2}, F_{2k} + F_{2k-5}, F_{2k+1} - F_{2k-4}, F_{2k+1} + F_{2k-3} }, where F (A000045) are the Fibonacci numbers and k and other subscripts are restricted to positive values.
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