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A076634
Coefficient of x^a(n) in (x+1/2)*(x+2/2)*...*(x+n/2) is the largest one.
2
1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
OFFSET
1,3
PROG
(PARI) a(n) = my(p=prod(j=1, n, x+j/2), m=vecmax(Vec(p))); for (i=0, poldegree(p), if (polcoef(p, i)==m, return(i))); \\ Michel Marcus, Feb 19 2021
(Python)
from sympy import prod, Poly
from sympy.abc import x
def A076634(n):
y = Poly(prod(2*x+i for i in range(1, n+1))).all_coeffs()[::-1]
return y.index(max(y)) # Chai Wah Wu, Mar 07 2021
CROSSREFS
Cf. A076620.
Sequence in context: A124230 A330780 A090973 * A083277 A274011 A307726
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Nov 10 2002
STATUS
approved