Number of zero-sum -n..n arrays of 7 elements with first and second differences also in -n..n.
A201878
Number of zero-sum -n..n arrays of 7 elements with first and second differences also in -n..n.
Terms
- a(0) =21a(1) =345a(2) =2509a(3) =11107a(4) =36569a(5) =99143a(6) =232969a(7) =492307a(8) =958025a(9) =1743993a(10) =3006947a(11) =4955757a(12) =7859017a(13) =12059931a(14) =17987847a(15) =26166137a(16) =37233755a(17) =51958111a(18) =71242519a(19) =96156041a(20) =127946965a(21) =168048881a(22) =218120357a(23) =280058879a(24) =356003167a(25) =448386363
External references
- oeis: A201878