A242021 Decimal expansion of the asymptotic growth rate of the number of odd coefficients in Pascal trinomial triangle mod 2.

7, 2, 7, 4, 5, 0, 9, 1, 3, 2, 4, 0, 0, 2, 2, 8, 1, 4, 3, 2, 6, 6, 1, 7, 2, 3, 5, 5, 6, 4, 5, 2, 0, 4, 5, 2, 5, 9, 0, 1, 7, 1, 0, 3, 5, 2, 0, 2, 1, 2, 7, 7, 5, 3, 0, 7, 1, 5, 6, 6, 8, 3, 9, 8, 7, 1, 8, 4, 1, 5, 0, 8, 8, 2, 8, 1, 4, 5, 2, 4, 2, 4, 7, 5, 3, 2, 9, 3, 1, 6, 3, 1, 0, 9, 1, 0, 3, 1, 6, 4

Offset

0,1

Links

Table of n, a(n) for n=0..99.

Steven Finch, Pascal Sebah and Zai-Qiao Bai, Odd Entries in Pascal's Trinomial Triangle (arXiv:0802.2654) p. 10.

Formula

log(abs(mu))/log(2) - 1, where mu is the root of x^4 - 3*x^3 - 2*x^2 + 2*x + 4 with maximum modulus.

Example

0.727450913240022814326617235564520452590171035202127753...

Mathematica

mu = Sort[Table[Root[x^4 - 3*x^3 - 2*x^2 + 2*x + 4, x, n], {n, 1, 4}], N[Abs[#1]] < N[Abs[#2]]&] // Last; RealDigits[Log[Abs[mu]]/Log[2] - 1, 10, 100] // First

Crossrefs

Sequence in context: A328904 A352301 A177437 * A096052 A003677 A301864

Adjacent sequences: A242018 A242019 A242020 * A242022 A242023 A242024

Keyword

nonn,cons,easy

Author

Jean-François Alcover, Aug 11 2014

Status

approved