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.

A079618 Triangle of coefficients in polynomials for partial sums of powers, scaled to produce integers: Sum_{i=1..m} i^(n-1) = Sum_{k=1..n} T(n,k)*m^k/A064538(n-1).

Original entry on oeis.org

1, 1, 1, 1, 3, 2, 0, 1, 2, 1, -1, 0, 10, 15, 6, 0, -1, 0, 5, 6, 2, 1, 0, -7, 0, 21, 21, 6, 0, 2, 0, -7, 0, 14, 12, 3, -3, 0, 20, 0, -42, 0, 60, 45, 10, 0, -3, 0, 10, 0, -14, 0, 15, 10, 2, 5, 0, -33, 0, 66, 0, -66, 0, 55, 33, 6, 0, 10, 0, -33, 0, 44, 0, -33, 0, 22, 12, 2, -691, 0, 4550, 0, -9009, 0, 8580, 0, -5005, 0, 2730, 1365, 210
Offset: 1

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Author

Henry Bottomley, Jan 29 2003

Keywords

Comments

Rosinger connects this sequence to Weisstein's Faulhaber's Formula page. Rosinger also discusses, without reference to OEIS, (1.1) A000217 Triangular numbers: a(n) = C(n+1,2) = n*(n+1)/2 = 0+1+2+...+n; (1.2) A000330 Square pyramidal numbers: 0^2+1^2+2^2+...+n^2 = n*(n+1)*(2n+1)/6; (1.4) A033312 n! - 1 [with different offset and the formula 1*1! + 2*2! + 3*3! + ...]; (1.4) A007489 Sum_{k=1..n} k!. - Jonathan Vos Post, Feb 22 2007

Examples

			Triangle T(n, k) begins:
n\k 1   2   3   4   5    6   7   8   9 10 ...
1:  1
2:  1   1
3:  1   3   2
4:  0   1   2   1
5: -1   0  10  15   6
6:  0  -1   0   5   6    2
7:  1   0  -7   0  21   21   6
8:  0   2   0  -7   0   14  12   3
9: -3   0  20   0 -42    0  60  45  10
10: 0  -3   0  10   0  -14   0  15  10  2
... Reformatted. - _Wolfdieter Lang_, Feb 02 2015
For example row n=7: partial sums of 6th powers (A000540)
  1^6+2^6+...+m^6 = (m-7*m^3+21*m^5+21*m^6+6*m^7)/42.
		

References

  • Conway, J. H. and Guy, R. K. The Book of Numbers. New York: Springer-Verlag, p. 106, 1996.

Crossrefs

Programs

  • Maple
    T := proc(n, k) option remember; local A, B;
    A := proc(n) option remember; denom((bernoulli(n+1,x)-bernoulli(n+1))/(n+1)) end:
    B := proc(n) option remember; add(T(n,j),j=2..n) end;
    if k>1 then T(n-1,k-1)*(n-1)*A(n-1)/(k*A(n-2)) elif n>1 then A(n-1)-B(n) else 1 fi end: seq(print(seq(T(n,k),k=1..n)),n=1..10); # Peter Luschny, Feb 02 2015
    # Alternative:
    A079618row := proc(n) bernoulli(n,x); (subs(x=x+1,%)-subs(x=1,%))/n;
    seq(coeff(numer(%),x,k), k=1..n) end:
    seq(A079618row(n), n=1..13); # Peter Luschny, Jul 14 2020
  • Mathematica
    T[n_, k_] := T[n, k] = Module[{A, B}, A[m_] := A[m] = Denominator[ Together[ (BernoulliB[m+1, x] - BernoulliB[m+1])/(m+1)]]; B[m_] := B[m] = Sum[T[m, j], {j, 2, m}]; Which[k>1, T[n-1, k-1]*(n-1)*A[n-1]/(k*A[n-2]), n>1, A[n-1] - B[n], True, 1]]; Table[Table[T[n, k], {k, 1, n}], {n, 1, 10}] // Flatten (* Jean-François Alcover, Sep 04 2015, after Peter Luschny *)
  • PARI
    row(p) = {v = vector(p+1, k, (-1)^(k==p)*binomial(p+1, k)*bernfrac(p+1-k))/(p+1); lcmd = lcm(vector(#v, k, denominator(v[k]))); v*lcmd;}
    tabl(nn) = for (n=0, nn, print(row(n))); \\ Michel Marcus, Feb 16 2016

Formula

T(n, k) = T(n-1, k-1) * (n-1) * A064538(n-1) / (k*A064538(n-2)) for k>1; T(n, 1) = A064538(n-1) - Sum_{k=2..n} T(n, k) for n>1; T(1, 1)=1.

Extensions

Edited. Offset corrected from 0 to 1. Typo in formula corrected. - Wolfdieter Lang, Feb 02 2015