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.

A260613 Triangle read by rows: T(n, k) = coefficient of x^(n-k) in Product_{m=1..n} (x+prime(m)); 0 <= k <= n, n >= 0.

Original entry on oeis.org

1, 1, 2, 1, 5, 6, 1, 10, 31, 30, 1, 17, 101, 247, 210, 1, 28, 288, 1358, 2927, 2310, 1, 41, 652, 5102, 20581, 40361, 30030, 1, 58, 1349, 16186, 107315, 390238, 716167, 510510, 1, 77, 2451, 41817, 414849, 2429223, 8130689, 14117683, 9699690
Offset: 0

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Author

Matthew Campbell, Aug 10 2015

Keywords

Comments

Up to signs and order of coefficients the same as A070918. Except for signs and the first column the same as A238146. - M. F. Hasler, Aug 13 2015

Examples

			The triangle starts:
Row 0: 1;
Row 1: 1, 2;  Coefficients of x + 2.
Row 2: 1, 5, 6;  Coefficients of (x+2)(x+3) = x^2 + 5x + 6.
Row 3: 1, 10, 31, 30; Coeff's of (x+2)(x+3)(x+5) = x^3 + 10x^2 + 31x + 30.
Row 5: 1, 17, 101, 247, 210;
Row 6: 1, 28, 288, 1358, 2927, 2310;
...
		

Crossrefs

Main diagonal gives A002110.
Row sums give A054640.
Cf. A000040.

Programs

  • Maple
    T:= n-> (p-> seq(coeff(p, x, n-i), i=0..n))(mul(x+ithprime(i), i=1..n)):
    seq(T(n), n=0..10);  # Alois P. Heinz, Aug 18 2019
  • Mathematica
    row[n_] := CoefficientList[Product[x + Prime[m], {m, 1, n}] + O[x]^(n+1), x] // Reverse;
    row /@ Range[0, 8] // Flatten (* Jean-François Alcover, Sep 16 2019 *)
  • PARI
    tabl(nn) = {for (n=0, nn, polp = prod(k=1, n, x+prime(k)); forstep (k= n, 0, -1, print1(polcoeff(polp, k), ", ");); print(););} \\ Michel Marcus, Aug 10 2015

Formula

T(n, 1) = A007504(n) for n >= 1.
T(n, 2) = A024447(n) for n >= 2.

Extensions

Corrected and edited by M. F. Hasler, Aug 13 2015
a(20) in b-file corrected by Andrew Howroyd, Dec 31 2017