OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..22
R. Chapman, A polynomial taking integer values, Mathematics Magazine, 29 (1996), 121.
MATHEMATICA
PROG
(Magma) F:= Factorial; [1] cat [(&*[(&*[2^(k+1) - 2^(j): j in [1..k]])/Factorial(k): k in [1..n-1]]): n in [2..20]]; // G. C. Greubel, Sep 19 2023
(SageMath) f=factorial; [product(product(2^(k+1) - 2^j for j in range(1, k+1))//factorial(k) for k in range(1, n)) for n in range(1, 21)] // G. C. Greubel, Sep 19 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 02 2012
EXTENSIONS
Name edited by Michel Marcus, May 17 2019
STATUS
approved