S(n; 2,0) where S(n; t,s) is the number of length n 4-ary strings whose digits sum to t mod 4 and whose sum of products of all pairs of digits sum to s mod 4.

A068789

S(n; 2,0) where S(n; t,s) is the number of length n 4-ary strings whose digits sum to t mod 4 and whose sum of products of all pairs of digits sum to s mod 4.

Terms

    a(0) =1a(1) =2a(2) =4a(3) =16a(4) =56a(5) =272a(6) =1184a(7) =4608a(8) =17536a(9) =65792a(10) =254464a(11) =1017856a(12) =4130816a(13) =16781312a(14) =67641344a(15) =270532608a(16) =1077968896a(17) =4295032832a(18) =17146445824a(19) =68585783296a(20) =274609995776

External references