a(n) = [x^n/n!] Sum_{k=0..n} cosh(k*x)^k.
A249489
a(n) = [x^n/n!] Sum_{k=0..n} cosh(k*x)^k.
Terms
- a(0) =1a(1) =0a(2) =9a(3) =0a(4) =12070a(5) =0a(6) =126447741a(7) =0a(9) =0a(11) =0a(13) =0a(15) =0a(17) =0
External references
- oeis: A249489
A249489
a(n) = [x^n/n!] Sum_{k=0..n} cosh(k*x)^k.