求数列通项公式（希望三种以上）

基本粒子

a(n)=a(n-2)-1，如果遇到0，改为9。

zhongjunzhang

把数字两个两个分组，1组，4321987654321…，2组，876543219876…。
483726159循环
+4-5循环

Kay_Young

a_n = (9+4*e^16ipi/9+8*e^14ipi/9+3*e^4ipi/3+7*e^10ipi/9+2*e^8ipi/9+6*e^2ipi/3+1*e^4ipi/9+5*e^2ipi/9)e^(2niPi/9)+(9+4*e^14ipi/9+8*e^10ipi/9+3*e^2ipi/3+7*e^2ipi/9+2*e^16ipi/9+6*e^4ipi/3+1*e^8ipi/9+5*e^4ipi/9)e^(4niPi/9)+(18+12*e^4ipi/3+15*e^2ipi/3)e^(2niPi/3)+(9+4*e^10ipi/9+8*e^2ipi/9+3*e^4ipi/3+7*e^4ipi/9+2*e^14ipi/9+6*e^2ipi/3+1*e^16ipi/9+5*e^8ipi/9)e^(2niPi/9)e^(8niPi/9)+(9+4*e^8ipi/9+8*e^16ipi/9+3*e^2ipi/3+7*e^14ipi/9+2*e^4ipi/9+6*e^4ipi/3+1*e^2ipi/9+5*e^10ipi/9)e^(10niPi/9)+(18+12*e^2ipi/3+15*e^4ipi/3)e^(4niPi/3)+(9+4*e^4ipi/9+8*e^8ipi/9+3*e^4ipi/3+7*e^16ipi/9+2*e^2ipi/9+6*e^2ipi/3+1*e^10ipi/9+5*e^14ipi/9)e^(14niPi/9)+(9+4*e^2ipi/9+8*e^4ipi/9+3*e^2ipi/3+7*e^8ipi/9+2*e^10ipi/9+6*e^4ipi/3+1*e^14ipi/9+5*e^16ipi/9)e^(16niPi/9)