A000749 -id:A000749 - cp's OEIS frontend

A001659 Expansion of bracket function.

1, 1, -1, 2, -5, 13, -33, 80, -184, 402, -840, 1699, -3382, 6750, -13716, 28550, -60587, 129579, -275915, 579828, -1197649, 2431775, -4870105, 9672634, -19173013, 38151533, -76521331, 154941608, -316399235, 649807589, -1337598675, 2751021907, -5640238583, 11513062785, -23389948481, 47310801199, -95345789479, 191616365385

Offset: 1

N. J. A. Sloane

sign

Inverse binomial transform of A006218.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

G. C. Greubel, Table of n, a(n) for n = 1..1000
H. W. Gould, Binomial coefficients, the bracket function and compositions with relatively prime summands, Fib. Quart. 2, issue 4, (1964), 241-260.

Cf. A000005, A000748, A000749, A000750, A006090, A006218.

Equals A038200(n-1) + A038200(n), n>1.

Table[Sum[(-1)^(n - k)*Binomial[n, k]*Sum[Floor[k/j], {j, 1, k}], {k, 0, n}], {n, 1, 50}] (* G. C. Greubel, Jul 02 2017 *)

a(n)=sum(j=0,n,(-1)^(n-j)*binomial(n,j)*sum(k=1,j,j\k))

a(n)=polcoeff(sum(k=1,n,x^k/((1+x)^k-x^k),x*O(x^n)),n)

a(n) = Sum_{j=0..n} ((-1)^(n-j)*binomial(n,j)*Sum_{k=1..j} floor(j/k)).
G.f.: Sum_{k>0} x^k/((1+x)^k-x^k).
G.f.: Sum_{k>0} tau(k)*x^k/(1+x)^k. - Vladeta Jovovic, Jun 24 2003
G.f.: Sum_{n>=1} z^n/(1-z^n) (Lambert series) where z=x/(1+x). - Joerg Arndt, Jan 30 2011
a(n) = Sum_{k=1..n} (-1)^(n-k)*binomial(n-1,k-1)*tau(k). - Ridouane Oudra, Aug 21 2021

Edited by Michael Somos, Jun 14 2003

A306915 Square array A(n,k), n >= 0, k >= 1, read by antidiagonals, where column k is the expansion of g.f. 1/((1-x)^k-x^k).

Original entry on oeis.org

1, 1, 2, 1, 2, 4, 1, 3, 4, 8, 1, 4, 6, 8, 16, 1, 5, 10, 11, 16, 32, 1, 6, 15, 20, 21, 32, 64, 1, 7, 21, 35, 36, 42, 64, 128, 1, 8, 28, 56, 70, 64, 85, 128, 256, 1, 9, 36, 84, 126, 127, 120, 171, 256, 512, 1, 10, 45, 120, 210, 252, 220, 240, 342, 512, 1024

Offset: 0

Seiichi Manyama, Mar 16 2019

			Square array begins:
     1,   1,   1,   1,   1,    1,    1,    1, ...
     2,   2,   3,   4,   5,    6,    7,    8, ...
     4,   4,   6,  10,  15,   21,   28,   36, ...
     8,   8,  11,  20,  35,   56,   84,  120, ...
    16,  16,  21,  36,  70,  126,  210,  330, ...
    32,  32,  42,  64, 127,  252,  462,  792, ...
    64,  64,  85, 120, 220,  463,  924, 1716, ...
   128, 128, 171, 240, 385,  804, 1717, 3432, ...
   256, 256, 342, 496, 715, 1365, 3017, 6436, ...

Seiichi Manyama, Antidiagonals n = 0..139, flattened

Columns (1+2),3-9 give A000079, A024495(n+2), A000749(n+3), A049016, A192080, A049017, A290995(n+7), A306939.

Cf. A039912, A101508, A306846, A306913, A306914, A307047, A307078, A307393.

A[n_, k_] := Sum[Binomial[n + k - 1, k*j + k - 1], {j, 0, Floor[n/k]}]; Table[A[n - k, k], {n, 0, 11}, {k, n, 1, -1}] // Flatten (* Amiram Eldar, May 25 2021 *)

A(n,k) = Sum_{j=0..floor(n/k)} binomial(n+k-1,k*j+k-1).

A(n,2*k) = Sum_{i=0..n} Sum_{j=0..n-i} binomial(i+k-1,k*j+k-1) * binomial(n-i+k-1,k*j+k-1). - Seiichi Manyama, Apr 07 2019

A006090 Expansion of bracket function.

Original entry on oeis.org

1, -6, 21, -56, 126, -252, 463, -804, 1365, -2366, 4368, -8736, 18565, -40410, 87381, -184604, 379050, -758100, 1486675, -2884776, 5592405, -10919090, 21572460, -43144920, 87087001, -176565486, 357913941, -723002336

Offset: 0

David Callan

sign

G. C. Greubel, Table of n, a(n) for n = 0..1000
H. W. Gould, Binomial coefficients, the bracket function and compositions with relatively prime summands, Fib. Quart. 2, issue 4, (1964), 241-260.
Problems Drive, Eureka, 37 (1974), 8-11, 32-33, 24-27. (Annotated scanned copy)
Index entries for linear recurrences with constant coefficients, signature (-6,-15,-20,-15,-6).

Column 6 of A307047.

Cf. A000748, A000749, A000750, A001659.

CoefficientList[Series[1/((1+x)^6-x^6),{x,0,30}],x] (* or *) LinearRecurrence[ {-6,-15,-20,-15,-6},{1,-6,21,-56,126},31] (* Harvey P. Dale, Oct 14 2016 *)

x='x+O('x^50); Vec(1/((1+x)^6-x^6)) \\ G. C. Greubel, Jul 02 2017

G.f.: 1/((1+x)^6-x^6).

a(n) = (-1)^n * Sum_{k=0..floor(n/6)} binomial(n+5,6*k+5). - Seiichi Manyama, Aug 05 2024

A307047 Square array A(n,k), n >= 0, k >= 1, read by antidiagonals, where column k is the expansion of g.f. 1/((1+x)^k-x^k).

Original entry on oeis.org

1, 1, 0, 1, -2, 0, 1, -3, 4, 0, 1, -4, 6, -8, 0, 1, -5, 10, -9, 16, 0, 1, -6, 15, -20, 9, -32, 0, 1, -7, 21, -35, 36, 0, 64, 0, 1, -8, 28, -56, 70, -64, -27, -128, 0, 1, -9, 36, -84, 126, -125, 120, 81, 256, 0, 1, -10, 45, -120, 210, -252, 200, -240, -162, -512, 0

Offset: 0

Seiichi Manyama, Mar 21 2019

			Square array begins:
   1,    1,    1,    1,    1,    1,     1,     1, ...
   0,   -2,   -3,   -4,   -5,   -6,    -7,    -8, ...
   0,    4,    6,   10,   15,   21,    28,    36, ...
   0,   -8,   -9,  -20,  -35,  -56,   -84,  -120, ...
   0,   16,    9,   36,   70,  126,   210,   330, ...
   0,  -32,    0,  -64, -125, -252,  -462,  -792, ...
   0,   64,  -27,  120,  200,  463,   924,  1716, ...
   0, -128,   81, -240, -275, -804, -1715, -3432, ...
   0,  256, -162,  496,  275, 1365,  2989,  6436, ...

Seiichi Manyama, Antidiagonals n = 0..139, flattened

Columns 1-7 give A000007, A122803, A000748, (-1)^n * A000749(n+3), A000750, A006090, A049018.

Cf. A039912 (square array A(n,k), n >= 0, k >= 2), A306913, A306914, A306915.

T[n_, k_] := (-1)^n * Sum[(-1)^(j * Mod[k, 2]) * Binomial[n + k - 1, k*j + k - 1], {j, 0, Floor[n/k]}]; Table[T[n - k, k], {n, 0, 11}, {k, n, 1, -1}] // Flatten (* Amiram Eldar, May 20 2021 *)

A(n,k) = (-1)^n * Sum_{j=0..floor(n/k)} (-1)^((k mod 2) * j) * binomial(n+k-1,k*j+k-1).

A101508 Product of binomial matrix and the Mobius matrix A051731.

Original entry on oeis.org

1, 2, 1, 4, 2, 1, 8, 4, 3, 1, 16, 8, 6, 4, 1, 32, 16, 11, 10, 5, 1, 64, 32, 21, 20, 15, 6, 1, 128, 64, 42, 36, 35, 21, 7, 1, 256, 128, 85, 64, 70, 56, 28, 8, 1, 512, 256, 171, 120, 127, 126, 84, 36, 9, 1, 1024, 512, 342, 240, 220, 252, 210, 120, 45, 10, 1, 2048, 1024, 683, 496, 385, 463, 462, 330, 165, 55, 11, 1

Offset: 0

Paul Barry, Dec 05 2004

Row sums are A101509. Diagonal sums are A101510.
The matrix inverse appears to be A128313. - R. J. Mathar, Mar 22 2013
Read as upper triangular matrix, this can be seen as "recurrences in A135356 applied to A023531" [Paul Curtz, Mar 03 2017]. - The columns are: A000079, A131577, A024495, A000749, A139761, ... Column n differs after the (n+1)-th nonzero term on from the binomial coefficients C(k,n). - M. F. Hasler, Mar 05 2017

			Rows begin
  1;
  2,1;
  4,2,1;
  8,4,3,1;
  16,8,6,4,1;
  ...

Alois P. Heinz, Rows n = 0..140, flattened

A101508 := proc(n,k)
    a := 0 ;
    for i from 0 to n do
        if modp(i+1,k+1) = 0 then
            a := a+binomial(n,i) ;
        end if;
    end do:
    return a;
end proc: # R. J. Mathar, Mar 22 2013

t[n_, k_] := Sum[If[Mod[i + 1, k + 1] == 0, Binomial[n, i], 0], {i, 0, n}]; Table[t[n, k], {n, 0, 11}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jan 24 2014 *)

T(n,k)=sum(i=0,n, if((i+1)%(k+1)==0, binomial(n, i))) \\ M. F. Hasler, Mar 05 2017

T(n, k) = Sum_{i=0..n} if(mod(i+1, k+1)=0, binomial(n, i), 0).

Rows have g.f. x^k/((1-x)^(k+1)-x^(k+1)).

A038520 Number of elements of GF(2^n) with trace 1 and subtrace 0.

Original entry on oeis.org

0, 1, 0, 3, 4, 6, 20, 28, 64, 136, 240, 528, 1024, 2016, 4160, 8128, 16384, 32896, 65280, 131328, 262144, 523776, 1049600, 2096128, 4194304, 8390656, 16773120, 33558528, 67108864, 134209536, 268451840, 536854528, 1073741824

Offset: 0

Frank Ruskey

Colin Barker, Table of n, a(n) for n = 0..1000
F. Ruskey, Number of irreducible polynomials over GF(2) with given trace and subtrace
F. Ruskey, Number of elements of GF(2^n) with given trace and subtrace
Index entries for linear recurrences with constant coefficients, signature (0,2,4).

Cf. A038504, A000749, A038518, A038519, A038521.

LinearRecurrence[{0,2,4},{0,1,0,3},40] (* Harvey P. Dale, Oct 15 2017 *)

concat(0, Vec(x*(1 + x^2) / ((1 - 2*x)*(1 + 2*x + 2*x^2)) + O(x^40))) \\ Colin Barker, Aug 02 2019

a(n) = C(n, r+0)+C(n, r+4)+C(n, r+8)+... where r = 1 if n odd, r = 3 if n even.
a(n) = 2*a(n-2) + 4*a(n-3), n > 3. - Paul Curtz, Feb 06 2008
From Colin Barker, Aug 02 2019: (Start)
G.f.: x*(1 + x^2) / ((1 - 2*x)*(1 + 2*x + 2*x^2)).
a(n) = (2^n + i*((-1-i)^n - (-1+i)^n)) / 4 for n>0, where i=sqrt(-1).
(End)

A094266 LQTL Lean Quaternary Temporal Logic: a terse form of temporal logic created by assigning four descriptors such that false, becoming true, true and becoming false are represented and become a linear sequence. In a branching tree two alternative are open, change or no change. The integer sequence above is the count of the row possibilities of the four states over successive iterations.

Original entry on oeis.org

1, 1, 0, 0, 1, 2, 1, 0, 1, 3, 3, 1, 2, 4, 6, 4, 6, 6, 10, 10, 16, 12, 16, 20, 36, 28, 28, 36, 72, 64, 56, 64, 136, 136, 120, 120, 256, 272, 256, 240, 496, 528, 528, 496, 992, 1024, 1056, 1024, 2016, 2016, 2080, 2080, 4096, 4032, 4096, 4160, 8256, 8128, 8128, 8256, 16512

Offset: 0

Robert H Barbour and L. D. Painter, Jun 01 2004

This is a table read by rows of length 4. Every row is formed from the previous one by the circular Pascal triangle-like rule: a, b, c, d -> d+a, a+b, b+c, c+d. Consider a labeled binary tree such that the root has label 0 and every node labeled k has children labeled k and (k+1) mod 4; the n-th row of this sequence counts nodes on the level n+1 with labels 0, 1, 2, 3, while the n-th row of A099423 counts nodes up to level n. - Andrey Zabolotskiy, Jan 06 2023

Robert H. Barbour, 2D Four-Color Cellular Automaton, NKS 2006 Wolfram Science Conference.
Robert H. Barbour, Two-dimensional Four Color Cellular Automaton: Surface Explorations, Complex Systems, 17 (2007), 103-112.

Cf. A000749, A005418, A038503, A038504, A038505, A020522, A063376.

Algorithm available from Robert H Barbour

Appears to satisfy a 12-degree linear recurrence. - Ralf Stephan, Dec 04 2004

A140344 Catalan triangle A009766 prepended by n zeros in its n-th row.

Original entry on oeis.org

1, 0, 1, 1, 0, 0, 1, 2, 2, 0, 0, 0, 1, 3, 5, 5, 0, 0, 0, 0, 1, 4, 9, 14, 14, 0, 0, 0, 0, 0, 1, 5, 14, 28, 42, 42, 0, 0, 0, 0, 0, 0, 1, 6, 20, 48, 90, 132, 132, 0, 0, 0, 0, 0, 0, 0, 1, 7, 27, 75, 165, 297, 429, 429, 0, 0, 0, 0, 0, 0, 0, 0, 1, 8, 35, 110, 275, 572, 1001, 1430, 1430

Offset: 0

Paul Curtz, May 29 2008

The triangle's n-th row is also related to recurrences for sequences f(n) which p-th differences, p=n+2: The denominator of the generating function contains a factor 1-2x in these cases.
This factor may be "lifted" either by looking at auxiliary sequences f(n+1)-2f(n) or by considering the corresponding "degenerate" shorter recurrences right away. In the case p=4, the recurrence is f(n)=4f(n-1)-6f(n-2)+4f(n-3) from the 4th row in A135356, the denominator in the g.f. is 1-4x+6x^2-4x^3=(1-2x)(1-2x+2x^2), which yields the degenerate recurrence f(n)=2f(n-1)-2f(n-2) from the 2nd factor and leaves the first three coefficients of 1/(1-2x+2x^2)=1+2x+2x^2+.. in row 2.
A000749 is an example which follows the recurrence but not the degenerate recurrence, but still A000749(n+1)-2A000749(n) = 0, 0, 1, 2, 2,.. starts with the 3 coefficients. A009545 follows both recurrences and starts with the three nonzero terms because there is only a power of x in the numerator of the g.f.
In the case p=5, the recurrence is f(n)=5f(n-1)-10f(n-2)+10f(n-3)-5f(n-4)+2f(n-5), the denominator in the g.f. is 1-5x+10x^2-10x^3+5x^4-2x^5= (1-2x)(1-3x+4x^2-2x^3+x^4), where 1/(1-3x+4x^2-2x^3+x^4) = 1+3x+5x^2+5x^3+... and the 4 coefficients populate row 3.
A049016 obeys the main recurrence but not the degenerate recurrence f(n)=3f(n-1)-4f(n-2)+2f(n-3)-f(n-4), yet A049016(n+1)-2A049016(n)=1, 3, 5, 5,.. starts with the 4 coefficients. A138112 obeys both recurrences and is constructed to start with the 4 coefficients themselves.
In the nomenclature of Foata and Han, this is the doubloon polynomial triangle d_{n,m}(0), up to index shifts. - R. J. Mathar, Jan 27 2011

			Triangle starts
1;
0,1,1;
0,0,1,2,2;
0,0,0,1,3,5,5;
0,0,0,0,1,4,9,14,14;

D. Foata, G.-N. Han, The doubloon polynomial triangle, Ramanujan J. 23 (2010), 107-126

Cf. A135356, A130020, A139687, A140343 (p=6), A140342 (p=7).

Table[Join[Array[0&, n], Table[Binomial[n+k, n]*(n-k+1)/(n+1), {k, 0, n}]], {n, 0, 8}] // Flatten (* Jean-François Alcover, Dec 16 2014 *)

Edited by R. J. Mathar, Jul 10 2008

A156232 a(n) is the number of induced subgraphs with odd number of edges in the cycle graph C(n).

Original entry on oeis.org

0, 4, 4, 16, 24, 64, 112, 256, 480, 1024, 1984, 4096, 8064, 16384, 32512, 65536, 130560, 262144, 523264, 1048576, 2095104, 4194304, 8384512, 16777216, 33546240, 67108864, 134201344, 268435456, 536838144, 1073741824, 2147418112

Offset: 2

Alessandro Cosentino (cosenal(AT)gmail.com), Feb 06 2009

nonn

Essentially the same sequence (see A204696) appears in the Cusick-Stanica paper.

G. C. Greubel, Table of n, a(n) for n = 2..1000
Thomas W. Cusick, and Pantelimon Stanica, Fast evaluation, weights and nonlinearity of rotation-symmetric functions, Discrete Math. 258 (2002), no. 1-3, 289-301.
Index entries for linear recurrences with constant coefficients, signature (2, 2, -4).

Cf. A000749, A032085.

RecurrenceTable[{a[n]== 2*a[n-1]  + 2*a[n-2] - 4*a[n-3], a[0]==0, a[1]==4, a[2]==4}, a, {n,0,50}] (* G. C. Greubel, Aug 26 2015 *)
LinearRecurrence[{2, 2, -4}, {0, 4, 4}, 40] (* Vincenzo Librandi, Aug 27 2015 *)

Vec(4*x^3*(1-x)/((1-2*x)*(1-2*x^2)) + O(x^40)) \\ Michel Marcus, Aug 26 2015

a(n) = 2^(n-1) - 2^(n/2) if n is even, 2^(n-1) otherwise.
G.f.: 4*x^3*(1-x)/((1-2*x)*(1-2*x^2)). a(n)=2*a(n-1)+2*a(n-2)-4*a(n-3). - R. J. Mathar, Feb 10 2009
E.g.f.: 2*(exp(2*x) - cosh(sqrt(2)*x)). - G. C. Greubel, Aug 26 2015

More terms from R. J. Mathar, Feb 10 2009

A307393 Square array A(n,k), n >= 0, k >= 1, read by antidiagonals, where column k is the expansion of g.f. ((1-x)^(k-4))/((1-x)^k-x^k).

Original entry on oeis.org

1, 1, 5, 1, 4, 16, 1, 4, 11, 42, 1, 4, 10, 26, 99, 1, 4, 10, 21, 57, 219, 1, 4, 10, 20, 42, 120, 466, 1, 4, 10, 20, 36, 84, 247, 968, 1, 4, 10, 20, 35, 64, 169, 502, 1981, 1, 4, 10, 20, 35, 57, 120, 340, 1013, 4017, 1, 4, 10, 20, 35, 56, 93, 240, 682, 2036, 8100

Offset: 0

Seiichi Manyama, Apr 07 2019

			Square array begins:
     1,   1,   1,   1,   1,   1,   1,   1, ...
     5,   4,   4,   4,   4,   4,   4,   4, ...
    16,  11,  10,  10,  10,  10,  10,  10, ...
    42,  26,  21,  20,  20,  20,  20,  20, ...
    99,  57,  42,  36,  35,  35,  35,  35, ...
   219, 120,  84,  64,  57,  56,  56,  56, ...
   466, 247, 169, 120,  93,  85,  84,  84, ...
   968, 502, 340, 240, 165, 130, 121, 120, ...

Seiichi Manyama, Antidiagonals n = 0..139, flattened

Columns 1-5 give A002662(n+3), A125128(n+1), A111927(n+3), A000749(n+3), A139748(n+3).

Cf. A306915, A306846, A307078, A307394.

T[n_, k_] := Sum[Binomial[n+3, k*j + 3], {j, 0, Floor[n/k]}]; Table[T[n - k, k], {n, 0, 11}, {k, n, 1, -1}] // Flatten (* Amiram Eldar, May 20 2021 *)

A(n,k) = Sum_{j=0..floor(n/k)} binomial(n+3,k*j+3).

A(n,2*k) = Sum_{i=0..n} Sum_{j=0..n-i} binomial(i+1,k*j+1) * binomial(n-i+1,k*j+1).

cp's OEIS Frontend

A001659 Expansion of bracket function.

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A306915 Square array A(n,k), n >= 0, k >= 1, read by antidiagonals, where column k is the expansion of g.f. 1/((1-x)^k-x^k).

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A006090 Expansion of bracket function.

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A307047 Square array A(n,k), n >= 0, k >= 1, read by antidiagonals, where column k is the expansion of g.f. 1/((1+x)^k-x^k).

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A101508 Product of binomial matrix and the Mobius matrix A051731.

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A038520 Number of elements of GF(2^n) with trace 1 and subtrace 0.

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A140344 Catalan triangle A009766 prepended by n zeros in its n-th row.

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