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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A347599 Irregular table read by rows, T(n, k) is the rank of the k-th Genocchi permutation of {1,...,n}, permutations sorted in lexicographical order. If no Genocchi permutation of {1,...,n} exists, then T(n, 1) = 0 by convention.

Original entry on oeis.org

1, 0, 5, 0, 67, 91, 92, 0, 1897, 2017, 2018, 2617, 2619, 2737, 2738, 2739, 2740, 3457, 3458, 3459, 3460, 4177, 4178, 4179, 4180, 0, 99241, 99961, 99962, 104281, 104283, 105001, 105002, 105003, 105004, 110041, 110042, 110043, 110044, 115081, 115082, 115083
Offset: 1

Views

Author

Peter Luschny, Sep 08 2021

Keywords

Comments

Let M be the n X n matrix with M(j, k) = floor((2*j - k ) / n). A Genocchi permutation of order n is a permutation sigma of {1,...,n} if Product_{k=1..n} M(k, sigma(k)) does not vanish.
Let P(n) denote the number of Genocchi permutations of order n. Zhi-Wei Sun conjectured, using permanents, that P(n - 1) = G(n), where G(n) are the Genocchi numbers A036968. From the well-known relation between Genocchi and Bernoulli numbers this implies, assuming the conjecture:
Bernoulli(n) = P(n - 1) / ((-1)^floor(n/2)*(2^(n + 2) - 2)) for n >= 2.
The related sequence A347600 lists Seidel permutations.

Examples

			Table starts:
[1] 1;
[2] 0;
[3] 5;
[4] 0;
[5] 67, 91, 92;
[6] 0;
[7] 1897, 2017, 2018, 2617, 2619, 2737, 2738, 2739, 2740, 3457, 3458, 3459, 3460, 4177, 4178, 4179, 4180;
.
The 17 permutations corresponding to the ranks are for n = 7:
1897 -> [3571246]; 2017 -> [3671245]; 2018 -> [3671254]; 2617 -> [4571236];
2619 -> [4571326]; 2737 -> [4671235]; 2738 -> [4671253]; 2739 -> [4671325];
2740 -> [4671352]; 3457 -> [5671234]; 3458 -> [5671243]; 3459 -> [5671324];
3460 -> [5671342]; 4177 -> [6571234]; 4178 -> [6571243]; 4179 -> [6571324];
4180 -> [6571342].
.
17 / (-510) = -1/30 = Bernoulli(8).
		

Crossrefs

Programs

  • Julia
    using Combinatorics
    function GenocchiPermutations(n)
        f(m) = m >= n ? 1 : m < 0 ? -1 : 0
        Mat(n) = [[f(2*j - k) for k in 1:n] for j in 1:n]
        M = Mat(n); P = permutations(1:n); R = Int64[]
        S, rank = 0, 1
        for p in P
            m = prod(M[k][p[k]] for k in 1:n)
            if m != 0
                S += m
                push!(R, rank)
            end
            rank += 1
        end
        # println(n, "  ", S, "  ", S // (2^(n + 2) - 2)) # Bernoulli number
        return R
    end
    for n in 1:11 println(GenocchiPermutations(n)) end

A239275 a(n) = numerator(2^n * Bernoulli(n, 1)).

Original entry on oeis.org

1, 1, 2, 0, -8, 0, 32, 0, -128, 0, 2560, 0, -1415168, 0, 57344, 0, -118521856, 0, 5749735424, 0, -91546451968, 0, 1792043646976, 0, -1982765704675328, 0, 286994513002496, 0, -3187598700536922112, 0, 4625594563496048066560, 0, -16555640873195841519616, 0, 22142170101965089931264, 0
Offset: 0

Views

Author

Paul Curtz, Mar 13 2014

Keywords

Comments

Difference table of f(n) = 2^n *A164555(n)/A027642(n) = a(n)/A141459(n):
1, 1, 2/3, 0, -8/15, 0, 32/21, 0,...
0, -1/3, -2/3, -8/15, 8/15, 32/21, -32/21,...
-1/3, -1/3, 2/15, 16/15, 104/105, -64/21,...
0, 7/15, 14/15, -8/105, -424/105,...
7/15, 7/15, -106/105, -416/105,...
0, -31/21, -62/31,
-31/21, -31/21,...
0,... etc.
Main diagonal: A212196(n)/A181131(n). See A190339(n).
First upper diagonal: A229023(n)/A181131(n).
The inverse binomial transform of f(n) is g(n). Reciprocally, the inverse binomial transform of g(n) is f(n) with -1 instead of f(1)=1, i.e., f(n) signed.
Sum of the antidiagonals: 1,1,0,-1,0,3,0,-17,... = (-1)^n*A036968(n) = -A226158(n+1).
Following A211163(n+2), f(n) is the coefficients of a polynomial in Pi^n.
Bernoulli numbers, twice, and Genocchi numbers, twice, are linked to Pi.
f(n) - g(n) = -A226158(n).
Also the numerators of the centralized Bernoulli polynomials 2^n*Bernoulli(n, x/2+1/2) evaluated at x=1. The denominators are A141459. - Peter Luschny, Nov 22 2015
(-1)^n*a(n) = 2^n*numerator(A027641(n)/A027642(n)) (that is the present sequence with a(1) = -1 instead of +1). - Wolfdieter Lang, Jul 05 2017

Crossrefs

Cf. A141459 (denominators), A001896/A001897, A027641/A027642.

Programs

  • Maple
    seq(numer(2^n*bernoulli(n, 1)), n=0..35); # Peter Luschny, Jul 17 2017
  • Mathematica
    Table[Numerator[2^n*BernoulliB[n, 1]], {n, 0, 100}] (* Indranil Ghosh, Jul 18 2017 *)
  • Python
    from sympy import bernoulli
    def a(n): return (2**n * bernoulli(n, 1)).numerator
    print([a(n) for n in range(51)]) # Indranil Ghosh, Jul 18 2017

Formula

a(n) = numerators of 2^n * A164555(n)/A027642(n).
Numerators of the binomial transform of A157779(n)/(interleave A001897(n), 1)(conjectured).

A297703 The Genocchi triangle read by rows, T(n,k) for n>=0 and 0<=k<=n.

Original entry on oeis.org

1, 1, 1, 2, 3, 3, 8, 14, 17, 17, 56, 104, 138, 155, 155, 608, 1160, 1608, 1918, 2073, 2073, 9440, 18272, 25944, 32008, 36154, 38227, 38227, 198272, 387104, 557664, 702280, 814888, 891342, 929569, 929569, 5410688, 10623104, 15448416, 19716064, 23281432, 26031912
Offset: 0

Views

Author

Peter Luschny, Jan 03 2018

Keywords

Examples

			The triangle starts:
0: [     1]
1: [     1,      1]
2: [     2,      3,      3]
3: [     8,     14,     17,     17]
4: [    56,    104,    138,    155,    155]
5: [   608,   1160,   1608,   1918,   2073,   2073]
6: [  9440,  18272,  25944,  32008,  36154,  38227,  38227]
7: [198272, 387104, 557664, 702280, 814888, 891342, 929569, 929569]
		

Crossrefs

Row sums are A005439 with offset 0.
T(n,0) = A005439 with A005439(0) = 1.
T(n,n) = A110501 with offset 0.

Programs

  • Julia
    function A297703Triangle(len::Int)
        A = fill(BigInt(0), len+2); A[2] = 1
        for n in 2:len+1
            for k in n:-1:2 A[k] += A[k+1] end
            for k in 2: 1:n A[k] += A[k-1] end
            println(A[2:n])
        end
    end
    println(A297703Triangle(9))
    
  • Python
    from functools import cache
    @cache
    def T(n):  # returns row n
        if n == 0: return [1]
        row = [0] + T(n - 1) + [0]
        for k in range(n, 0, -1): row[k] += row[k + 1]
        for k in range(2, n + 2): row[k] += row[k - 1]
        return row[1:]
    for n in range(9): print(T(n))  # Peter Luschny, Jun 03 2022

A227577 Square array read by antidiagonals, A(n,k) the numerators of the elements of the difference table of the Euler polynomials evaluated at x=1, for n>=0, k>=0.

Original entry on oeis.org

1, -1, 1, 0, -1, 0, 1, 1, -1, -1, 0, 1, 1, 1, 0, -1, -1, -1, 1, 1, 1, 0, -1, -1, -5, -1, -1, 0, 17, 17, 13, 5, -5, -13, -17, -17, 0, 17, 17, 47, 13, 47, 17, 17, 0, -31, -31, -107, -73, -13, 13, 73, 107, 31, 31, 0, -31, -31, -355
Offset: 0

Views

Author

Paul Curtz, Jul 16 2013

Keywords

Comments

The difference table of the Euler polynomials evaluated at x=1:
1, 1/2, 0, -1/4, 0, 1/2, 0, -17/8, ...
-1/2, -1/2, -1/4, 1/4, 1/2, -1/2, -17/8, 17/8, ...
0, 1/4, 1/2, 1/4; -1, -13/8, 17/4, 107/8, ...
1/4, 1/4, -1/4, -5/4, -5/8, 47/8, 73/8, -355/8, ...
0, -1/2, -1, 5/8 13/2, 13/4, -107/2, -655/8, ...
-1/2, -1/2, 13/8, 47/8, -13/4, -227/4, -227/8, 5687/8, ...
0, 17/8, 17/4, -73/8, -107/2, 227/8, 2957/4, 2957/8, ...
17/8, 17/8, -107/8, -355/8, 655/8, 5687/8, -2957/8, -107125/8, ...
To compute the difference table, take
1, 1/2;
-1/2;
The next term is always half of the sum of the antidiagonals. Hence (-1/2 + 1/2 = 0)
1, 1/2, 0;
-1/2, -1/2;
0;
The first column (inverse binomial transform) lists the numbers (1, -1/2, 0, 1/4, ..., not in the OEIS; corresponds to A027641/A027642). See A209308 and A060096.
A198631(n)/A006519(n+1) is an autosequence. See A181722.
Note the main diagonal: 1, -1/2, 1/2, -5/4, 13/2, -227/4, 2957/4, -107125/8, .... (See A212196/A181131.)
This twice the first upper diagonal. The autosequence is of the second kind.
From 0, -1, the algorithm gives A226158(n), full Genocchi numbers, autosequence of the first kind.
The difference table of the Bernoulli polynomials evaluated at x=1 is (apart from signs) A085737/A085738 and its analysis by Ludwig Seidel was discussed in the Luschny link. - Peter Luschny, Jul 18 2013

Examples

			Read by antidiagonals:
    1;
  -1/2,  1/2;
    0,  -1/2,   0;
   1/4,  1/4, -1/4, -1/4;
    0,   1/4,  1/2,  1/4,   0;
  -1/2, -1/2, -1/4,  1/4,  1/2,  1/2;
    0,  -1/2, - 1,  -5/4,  -1,  -1/2,   0;
  ...
Row sums: 1, 0, -1/2, 0, 1, 0, -17/4, 0, ... = 2*A198631(n+1)/A006519(n+2).
Denominators: 1, 1, 2, 1, 1, 1, 4, 1, ... = A160467(n+2)?
		

Crossrefs

Programs

  • Maple
    DifferenceTableEulerPolynomials := proc(n) local A,m,k,x;
    A := array(0..n,0..n); x := 1;
    for m from 0 to n do for k from 0 to n do A[m,k]:= 0 od od;
    for m from 0 to n do A[m,0] := euler(m,x);
       for k from m-1 by -1 to 0 do
          A[k,m-k] := A[k+1,m-k-1] - A[k,m-k-1] od od;
    LinearAlgebra[Transpose](convert(A, Matrix)) end:
    DifferenceTableEulerPolynomials(7);  # Peter Luschny, Jul 18 2013
  • Mathematica
    t[0, 0] = 1; t[0, k_] := EulerE[k, 1]; t[n_, 0] := -t[0, n]; t[n_, k_] := t[n, k] = t[n-1, k+1] - t[n-1, k]; Table[t[n-k, k] // Numerator, {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jul 18 2013 *)
  • Sage
    def DifferenceTableEulerPolynomialsEvaluatedAt1(n) :
        @CachedFunction
        def ep1(n):          # Euler polynomial at x=1
            if n < 2: return 1 - n/2
            s = add(binomial(n,k)*ep1(k) for k in (0..n-1))
            return 1 - s/2
        T = matrix(QQ, n)
        for m in range(n) :  # Compute difference table
            T[m,0] = ep1(m)
            for k in range(m-1,-1,-1) :
                T[k,m-k] = T[k+1,m-k-1] - T[k,m-k-1]
        return T
    def A227577_list(m):
        D = DifferenceTableEulerPolynomialsEvaluatedAt1(m)
        return [D[k,n-k].numerator() for n in range(m) for k in (0..n)]
    A227577_list(12)  # Peter Luschny, Jul 18 2013

Extensions

Corrected by Jean-François Alcover, Jul 17 2013

A227608 Denominators of A225825(n) difference table written by antidiagonals.

Original entry on oeis.org

1, 2, 2, 6, 3, 6, 2, 3, 3, 2, 30, 15, 15, 15, 30, 2, 15, 15, 15, 15, 2, 42, 21, 105, 105, 105, 21, 42, 2, 21, 21, 105, 105, 21, 21, 2, 30, 15, 105, 105, 105, 105, 105, 15, 30, 2, 15, 15, 105, 105, 105, 105, 15, 15, 2, 66, 33, 165, 165, 1155, 231, 1155, 165, 165, 33, 66, 2, 33, 33, 165, 165, 231, 231, 165, 165, 33, 33, 2
Offset: 0

Views

Author

Paul Curtz, Aug 10 2013

Keywords

Examples

			1,
-1/2,      1/2,
-1/6,     -2/3,     -1/6,
1/2,       1/3,     -1/3,     -1/2,
7/30,    11/15,    16/15,    11/15,     7/30,
-3/2,   -19/15,    -8/15,     8/15,    19/15,    3/2,
-31/42, -47/21, -368/105, -424/105, -368/105, -47/21, -31/42.
Row sums: 1, 0/2, -6/6, 0/6, 90/30, 0/30, -3570/210, 0/210, 32550/210,... .
Are the denominators A034386(n+1)?
Reduced row sums: 1, 0, -1, 0, 3, 0, -17, 0, 155,... = -A036968(n+1)? See A226158(n+2). First 100 terms checked by Jean-François Alcover.
		

Crossrefs

Programs

  • Mathematica
    max = 12; b[0] = 1; b[n_] := Numerator[ BernoulliB[n, 1/2] - (n+1)*EulerE[n, 0]]; t = Table[b[n], {n, 0, max}] / Table[ Sum[ Boole[ PrimeQ[d+1]]/(d+1), {d, Divisors[n]}] // Denominator, {n, 0, max}]; dt = Table[ Differences[t, n], {n, 0, max}]; Table[ dt[[n-k+1, k]] // Denominator, {n, 1, max}, {k, 1, n}] // Flatten (* Jean-François Alcover, Aug 12 2013 *)

Extensions

More terms from Jean-François Alcover, Aug 12 2013

A240485 a(n) = -Zeta(1-n)*n*(2^(n+1) - 4) - Zeta(-n)*(n+1)*(2^(n+2) - 2), for n = 0 the limit is understood.

Original entry on oeis.org

1, 3, 2, -1, -2, 3, 6, -17, -34, 155, 310, -2073, -4146, 38227, 76454, -929569, -1859138, 28820619, 57641238, -1109652905, -2219305810, 51943281731, 103886563462, -2905151042481, -5810302084962, 191329672483963, 382659344967926, -14655626154768697
Offset: 0

Views

Author

Paul Curtz, Apr 06 2014

Keywords

Comments

Let G(m, n) denote the difference table of a(n):
1, 3, 2, -1, -2, 3, 6, -17, -34,...
2, -1, -3, -1, 5, 3, -23, -17,...
-3, -2, 2, 6, -2, -26, 6,...
1, 4, 4, -8, -24, 32,...
3, 0, -12, -16, 56,...
-3, -12, -4, 72,...
-9, 8, 76,...
17, 68,...
51,...
a(n) = G(0, n).
The main diagonal G(n, n) = 1, -1, 2, -8, 56, -608,... is essentially a signed version of A005439.
The first upper diagonal is the main diagonal multiplied by 3. G(n, n+1) = 3*G(n, n).
G(m, n) = G(m, n-1) + G(m+1,n-1).
Inverse binomial transform: after 1, 2, -3, A110501(n+1) is interleaved with 3*A110501(n+1), signed two by two. I. e. b(n) = 1, 2, -3, 1, 3, -3, -9, 17, 51,... . a(n+2) + b(n+2) = -1, 0, 1, 0, -3, 0, 17,... = A226158(n+2).
This is particular to the Genocchi numbers. If the first upper diagonal is proportional to the main diagonal (1, -1, 2, -8,...), the sequence and the inverse binomial transform are simply connected to the Genocchi numbers.

Crossrefs

Programs

  • Maple
    A240485 := proc(n) if n = 0 then 1 elif n = 1 then 3 else
    m := 2*iquo(n-1, 2) + 2; -2^irem(n-1, 2)*m*euler(m-1, 0) fi end:
    seq(A240485(n), n=0..27); # Peter Luschny, Apr 09 2014
  • Mathematica
    a[n_] := Which[n == 0, 1, n == 1, 3, True, m = 2*Quotient[n-1, 2]+2; -2^Mod[n-1, 2]*m*EulerE[m-1, 0]]; Table[a[n], {n, 0, 27}] (* Jean-François Alcover, Apr 09 2014, after Peter Luschny *)
  • Sage
    def A240485(n):
        if n < 3: return [1,3,2][n]
        m = 2*((n+1)//2)
        b = 2*(1-2^m)*bernoulli(m)
        if is_even(n): b = 2*b
        return (-1)^ceil((n^2+1)/2)*b
    [A240485(n) for n in (0..24)]  # Peter Luschny, Apr 08 2014

Formula

a(2*n+1) = a(2*n+2)/2 for n > 0.
-a(2*n+2)/2 = A226158(2*n+2) = A001469(n+1) = (2*n+2)*E(2*n+1, 0) where E(n, x) are the Euler polynomials.
a(n) = -2*A226158(n) - A226158(n+1).
E.g.f.: (2*exp(x)*(3*x+exp(x)*(2*x+1)+1))/(exp(x)+1)^2. - Peter Luschny, Apr 10 2014

A277627 Square array read by antidiagonals downwards: T(n,k), n>=0, k>=0, in which column 0 is equal to A057427: 0, 1, 1, 1, ..., and for k > 0 column k lists two zeros followed by the partial sums of column k-1.

Original entry on oeis.org

0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 3, 1, 0, 0, 0, 0, 0, 1, 4, 1, 0, 0, 0, 0, 0, 0, 3, 5, 1, 0, 0, 0, 0, 0, 0, 0, 6, 6, 1, 0, 0, 0, 0, 0, 0, 0, 1, 10, 7, 1, 0, 0, 0, 0, 0, 0, 0, 0, 4, 15, 8, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 21, 9, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 20, 28, 10, 1
Offset: 0

Views

Author

Paul Curtz, Oct 24 2016

Keywords

Comments

In other words, for n > 0 the column k lists 2*k+1 zeros together with the partial sums of the positive terms of column k-1. - Omar E. Pol, Oct 25 2016
Comments from the author:
1) ZSPEC =
0, 0, 0, 0, 0, 0, 0, 0, ...
1, 0, 0, 0, 0, 0, 0, 0, ...
1, 0, 0, 0, 0, 0, 0, 0, ...
1, 1, 0, 0, 0, 0, 0, 0, ...
1, 2, 0, 0, 0, 0, 0, 0, ...
1, 3, 1, 0, 0, 0, 0, 0, ...
1, 4, 3, 0, 0, 0, 0, 0, ...
1, 5, 6, 1, 0, 0, 0, 0, ...
etc.
The columns are the autosequences of the first kind of the title (column 1: 0, 0, followed by A001477(n); column 2: 0, 0, 0, 0, followed by A000217(n), etc) .
The positive terms are the Pascal triangle written by diagonals (A011973).
First column: A060576(n+1). Or A057427(n), n>-1, thanks to Omar E. Pol.
Row sums: A000045(n), autosequence of the first kind.
Alternated row sums and subtractions: 0, 1, 1, 0, -1, -1, 0 = A128834(n), autosequence of the first kind.
Antidiagonal sums: 0, 1, 1, 1, 2, 3, 4, 6, ... = A078012(n+2).
Application.
Numbers in triangle leading to the Genocchi numbers -A226158(n).
We multiply the columns of ZSPEC by d(n) = 1, -1, 2, -8, 56, -608, ... from A005439.
Hence, with only the first 0,
0,
1,
1,
1, -1,
1, -2,
1, -3, 2,
1, -4, 6,
1, -5, 12, -8,
1, -6, 20, -32,
1, -7, 30, -80, 56,
1, -8, 42, -160, 280,
etc.
The row sums is -A226158(n).
2) Now consider the case of the autosequences of the second kind.
First step.
2, 1, 1, 1, 1, 1, ... = A054977(n)
0, 0, 2, 3, 4, 5, 6, 7, ... = A199969(n) with offset 0
0, 0, 0, 0, 2, 5, 9, 14, 20, 27, ... see A000096
etc.
The positive terms are ASPEC in A191302. By triangle, they are either A029653(n) with A029653(0) = 2 instead of 1 or A029635(n).
Second step. YSPEC =
2, 0, 0, 0, 0, 0, ...
1, 0, 0, 0, 0, 0, ...
1, 2, 0, 0, 0, 0, ...
1, 3, 0, 0, 0, 0, ...
1, 4, 2, 0, 0, 0, ...
1, 5, 5, 0, 0, 0, ...
1, 6, 9, 2, 0, 0, ...
1, 7, 14, 7, 0, 0, ...
etc.
Diagonals by triangle: A029635(n).
This is the companion to ZSPEC.
Row sums: A000032(n), autosequence of the second kind.
Alternated row sums and subtractions: period 6 repeat 2, 1, -1, -2, -1, 1 = A087204(n), autosequence of the second kind.
Application.
Numbers in triangle leading to A230324(n), a companion to -A226158(n).
We multiply the columns of YSPEC by d(n) 1, -1, 2, -8, 56, ... (see above).
Hence, without zeros:
2,
1,
1, -2,
1, -3,
1, -4, 4,
1, -5, 10,
1, -6, 18, -16,
1, -7, 28, -56,
1, -8, 40, -128, 112,
1, -9, 54, -240, 504,
etc.
The row sum is A230324(n).

Crossrefs

Cf. A011973 (without 0's), A007318 (Pascal's triangle).
Cf. A000045 (row sums), A078012 (antidiagonal sums).
Columns: A060576 or A057427 (k=0), A001477 (k=1), A000217 (k=2).

Programs

  • Mathematica
    kMax = 13; col[0] = Join[{0}, Array[1&, kMax]]; col[k_] := col[k] = Join[{0, 0}, col[k-1][[1 ;; -3]] // Accumulate]; T[n_, k_] := col[k][[n+1]]; Table[T[n-k, k], {n, 0, kMax}, {k, n, 0, -1}] // Flatten (* Jean-François Alcover, Nov 15 2016 *)

Extensions

Better definition from Omar E. Pol, Oct 25 2016

A240677 a(n) = 6*Zeta(1-n)*n*(2^n-1) - Zeta(-n)*(n+1)*(2^(n+2)-2), for n = 0 the limit is understood.

Original entry on oeis.org

1, -2, -3, -1, 3, 3, -9, -17, 51, 155, -465, -2073, 6219, 38227, -114681, -929569, 2788707, 28820619, -86461857, -1109652905, 3328958715, 51943281731, -155829845193, -2905151042481, 8715453127443
Offset: 0

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Author

Paul Curtz, Apr 10 2014

Keywords

Comments

G2(m, n), difference table of a(n):
1, -2, -3, -1, 3, 3, -9, -17, 51,...
-3, -1, 2, 4, 0, -12, -8, 68,...
2, 3, 2, -4, -12, 4, 76,...
1, -1, -6, -8, 16, 72,...
-2, -5, -2, 24, 56,...
-3, 3, 26, 32,...
6, 23, 6,...
17, -17,...
-34,...
etc.
The main diagonal G2(n,n) = 1, -1, 2, -8,... is essentially a signed version of A005439.
The first upper diagonal is the main diagonal multiplied by -2. G2(n, n+1) = -2*G2(n, n).
G2(m, n) = G2(m, n-1) + G2(m+1, n-1).
a(n) = (-1)^n*b(n) of A240485(n).
Inverse binomial transform: (-1)^n*A240485(n).
a(n) and A240485(n) are reciprocal. Like for instance (-1)^n and 2^n.

Crossrefs

Cf. A240485.

Programs

  • Maple
    A240677 := n -> `if`(n=0, 1, 6*Zeta(1-n)*n*(2^n-1) - Zeta(-n)*(n+1)*(2^(n+2)-2)); seq(A240677(n), n=0..24); # Peter Luschny, Apr 11 2014
  • Mathematica
    g[0] = 0; g[1] = -1; g[n_] := n*EulerE[n - 1, 0]; a[n_] := 3*g[n] - g[n + 1]; Table[a[n], {n, 0, 25}] (* Jean-François Alcover, Apr 10 2014 *)
  • PARI
    x = 'x+O('x^66);
    A = -2*exp(x)*(2*x+exp(x)*(3*x-1)-1)/(exp(x)+1)^2;
    Vec( serlaplace(A) )  /* Peter Luschny, Apr 10 2014 */

Formula

a(n) = 3*A226158(n) - A226158(n+1).
a(n+3) = -A001469(n+1).
a(2n+4) = -3*a(2n+3).
a(n) = A240485(n) + 5*A226158(n).
E.g.f.: -2*exp(x)*(2*x+exp(x)*(3*x-1)-1)/(exp(x)+1)^2. - Peter Luschny, Apr 10 2014

A278331 Shifted sequence of second differences of Genocchi numbers.

Original entry on oeis.org

0, -2, -2, 6, 14, -34, -138, 310, 1918, -4146, -36154, 76454, 891342, -1859138, -27891050, 57641238, 1080832286, -2219305810, -50833628826, 103886563462, 2853207760750, -5810302084962, -188424521441482, 382659344967926, 14464296482284734, -29311252309537394, -1277229462293249018
Offset: 0

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Author

Keywords

Comments

This is an autosequence of the first kind (array of successive differences shows typical zero diagonal).
Last digits are apparently of period 20.
From A226158(n) for the continuity of autosequences of the first kind.
b(n) = 0, 1, -1, 0, 1, 0, -3, 0, 17, ... = A226158(n) with 1 as second term instead of -1.
c(n) = 0, 0, -1, 0, 1, 0, -3, 0, 17, ... = A226158(n) with 0 as second term instead of -1.
Respective difference tables:
0, -1, -1, 0, 1, 0, -3, 0, 17, ...
-1, 0, 1, 1, -1, -3 , 3, 17, -17, ...
1, 1, 0, -2, -2, 6, 14, -34, -138, ...
etc,
0, 1, -1, 0, 1, 0, -3, 0, 17, ... = 0 followed by A036968(n+1)
1, -2, 1, 1, -1, -3, 3, 17, -17, ...
-3, 3, 0, -2, -2, 6, 14, -34, -138, ...
etc,
0, 0, -1, 0, 1, 0, -3, 0, 17, ...
0, -1, 1, 1, -1, -3, 3, 17, -17, ...
-1, 2, 0, -2, -2, 6, 14, -34, -138, ...
etc.
Since it is in the three tables, a(n) is the core of the Genocchi numbers.

Crossrefs

Cf. A001469, A014781, A036968, A005439 (a(n) second and third diagonals), A164555/A027642, A209308, A226158, A240581(n)/A239315(n) (core of Bernoulli numbers).

Programs

  • Mathematica
    g[0] = 0; g[1] = -1; g[n_] := n*EulerE[n-1, 0]; G = Table[g[n], {n, 0, 30}]; Drop[Differences[G, 2], 2]
    (* or, from Seidel's triangle A014781: *)
    max = 26; T[1, 1] = 1; T[n_, k_] /; 1 <= k <= (n + 1)/2 := T[n, k] = If[EvenQ[n], Sum[T[n - 1, i], {i, k, max}], Sum[T[n - 1, i], {i, 1, k}]]; T[, ] = 0; a[n_] := With[{k = Floor[(n - 1)/2] + 1}, (-1)^k*T[n + 3, k]]; Table[a[n], {n, 0, max}]

Formula

a(n) = (n+2)*E(n+1, 0) - 2*(n+3)*E(n+2, 0) + (n+4)*E(n+3, 0), where E(n,x) is the n-th Euler polynomial.
a(n) = -2*(2^(n+2)-1)*B(n+2) + 4*(2^(n+3)-1)*B(n+3) - 2*(2^(n+4)-1)*B(n+4), where B(n) is the n-th Bernoulli number.

A333303 T(n, k) = [x^k] (-2)^n*(B(n, x/2) - B(n, (x+1)/2)) where B(n, x) are the Bernoulli polynomials. Triangle read by rows, for 0 <= k <= n.

Original entry on oeis.org

0, 1, 1, -2, 0, -3, 3, -1, 0, 6, -4, 0, 5, 0, -10, 5, 3, 0, -15, 0, 15, -6, 0, -21, 0, 35, 0, -21, 7, -17, 0, 84, 0, -70, 0, 28, -8, 0, 153, 0, -252, 0, 126, 0, -36, 9, 155, 0, -765, 0, 630, 0, -210, 0, 45, -10, 0, -1705, 0, 2805, 0, -1386, 0, 330, 0, -55, 11
Offset: 0

Views

Author

Peter Luschny, May 07 2020

Keywords

Comments

Can be seen as the Bernoulli counterpart of the Euler triangles A247453 and A109449.

Examples

			B*(8, z) = 1024*(Zeta(-7, (z+1)/2) - Zeta(-7, z/2))
         = -17 + 84*z^2 - 70*z^4 + 28*z^6 - 8*z^7.
Triangle starts:
[ 0] [  0]
[ 1] [  1]
[ 2] [  1,    -2]
[ 3] [  0,    -3,    3]
[ 4] [ -1,     0,    6,   -4]
[ 5] [  0,     5,    0,  -10,   5]
[ 6] [  3,     0,  -15,    0,  15,    -6]
[ 7] [  0,   -21,    0,   35,   0,   -21,    7]
[ 8] [-17,     0,   84,    0, -70,     0,   28,  -8]
[ 9] [  0,   153,    0, -252,   0,   126,    0, -36,  9]
[10] [155,     0, -765,    0, 630,     0, -210,   0, 45, -10]
[11] [  0, -1705,    0, 2805,   0, -1386,    0, 330,  0, -55, 11]
		

Crossrefs

Row sums are (-1)^n*A226158(n). Alternating row sums are A239977(n).
Cf. A181983, A247453, A109449, (A053382/A053383) Bernoulli polynomials.

Programs

  • Mathematica
    B[n_, x_] := (-2)^n (BernoulliB[n, x/2] - BernoulliB[n, (x + 1)/2]);
    Prepend[Table[CoefficientList[B[n, x], x], {n, 1, 11}], 0] // Flatten
  • SageMath
    def Bstar(n,x):
        return (-2)^n*(bernoulli_polynomial(x/2,n) - bernoulli_polynomial((x+1)/2,n))
    print(flatten([expand(Bstar(n, x)).list() for n in (0..11)]))

Formula

Let B*(n, x) denote the alternating Bernoulli rational polynomial functions defined by Z*(s, x) = Phi(-1, s, x) and B*(s, x) = -s Z*(1 - s, x). Here Phi(z, s, x) is the Hurwitz-Lerch transcendent defined as an analytic continuation of Sum_{k>=0} z^k/(k+x)^s. Then T(n, k) = (-1)^n [x^k] 2 B*(n, x).
T(n, 0) = 2*(2^n - 1)*Bernoulli(n, 1) = n*Euler(n - 1, 1) = -A226158(n).
Main diagonal is (-1)^(n+1)*n = A181983(n).
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