A214407 - OEIS

A214407

Triangle read by rows. The coefficients in ascending order of x^i of the polynomials p{0}(x) = 1 and p{n}(x) = Sum_{k=0..n-1; k even} binomial(n, k) * p{k}(0)*(1 - n%2 + x^(n - k)).

1, 0, 1, 1, 0, 1, 0, 3, 0, 1, 7, 0, 6, 0, 1, 0, 35, 0, 10, 0, 1, 121, 0, 105, 0, 15, 0, 1, 0, 847, 0, 245, 0, 21, 0, 1, 3907, 0, 3388, 0, 490, 0, 28, 0, 1, 0, 35163, 0, 10164, 0, 882, 0, 36, 0, 1, 202741, 0, 175815, 0, 25410, 0, 1470, 0, 45, 0, 1, 0

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OFFSET

0,8

COMMENTS

Matrix inverse of a signed variant of A119467.

LINKS

Table of n, a(n) for n=0..66.

FORMULA

T(n, k) = n! * [y^k] [x^n] (exp(x * y) / (2 - cosh(x))). - Peter Luschny, May 06 2023

EXAMPLE

0, 1

1, 0, 1

0, 3, 0, 1

7, 0, 6, 0, 1

0, 35, 0, 10, 0, 1

121, 0, 105, 0, 15, 0, 1

0, 847, 0, 245, 0, 21, 0, 1

3907, 0, 3388, 0, 490, 0, 28, 0, 1

PROG

(Sage)

@CachedFunction

def A214407_poly(n, x) :

return 1 if n==0 else add(A214407_poly(k, 0)*binomial(n, k)*(x^(n-k)+1-n%2) for k in range(n)[::2])

def A214407_row(n) :

R = PolynomialRing(ZZ, 'x')

return R(A214407_poly(n, x)).coeffs()

for n in (0..8) : A214407_row(n)

CROSSREFS

Cf. A119467, A327034 (row sums), A094088 (column 0).

Sequence in context: A216802 A350248 A297786 * A298668 A137680 A248722

Adjacent sequences: A214404 A214405 A214406 * A214408 A214409 A214410

KEYWORD

nonn,tabl

AUTHOR

Peter Luschny, Jul 16 2012

STATUS

approved