Av(1243, 1324, 2143, 3421)
View Raw Data
Generating Function
x86x78x6+31x549x4+48x327x2+8x1(2x1)2(x1)5
Counting Sequence
1, 1, 2, 6, 20, 61, 164, 400, 915, 2014, 4341, 9263, 19686, 41783, 88642, ...
Implicit Equation for the Generating Function
(2x1)2(x1)5F(x)+x86x78x6+31x549x4+48x327x2+8x1=0
Recurrence
a(0)=1
a(1)=1
a(2)=2
a(3)=6
a(4)=20
a(5)=61
a(6)=164
a(7)=400
a(8)=915
a(n+2)=4a(n)+4a(n+1)+(n4)(3n334n2+41n18)24,n9
Explicit Closed Form
{54n=01+32nn8+15n2825n1211n312+n48otherwise

This specification was found using the strategy pack "Point Placements" and has 89 rules.

Found on January 18, 2022.

Finding the specification took 1 seconds.

This tree is too big to show here. Click to view tree on new page.

Copy 89 equations to clipboard:
F0(x)=F1(x)+F2(x)F1(x)=1F2(x)=F3(x)F3(x)=F12(x)F4(x)F4(x)=F25(x)+F5(x)F5(x)=F1(x)+F6(x)F6(x)=F7(x)F7(x)=F12(x)F8(x)F8(x)=F13(x)+F9(x)F9(x)=F1(x)+F10(x)F10(x)=F11(x)F11(x)=F12(x)F9(x)F12(x)=xF13(x)=F14(x)+F23(x)F14(x)=F15(x)F15(x)=F12(x)F16(x)F16(x)=F17(x)+F9(x)F17(x)=F18(x)+F21(x)F18(x)=F19(x)F19(x)=F12(x)F20(x)F20(x)=F1(x)+F18(x)F21(x)=F22(x)F22(x)=F12(x)F17(x)F23(x)=F24(x)F24(x)=F12(x)F13(x)F25(x)=F26(x)+F46(x)F26(x)=F27(x)F27(x)=F12(x)F28(x)F28(x)=F29(x)+F30(x)F29(x)=F1(x)+F14(x)F30(x)=F18(x)+F31(x)F31(x)=F32(x)+F33(x)+F38(x)F32(x)=0F33(x)=F12(x)F34(x)F34(x)=F10(x)+F35(x)F35(x)=F32(x)+F33(x)+F36(x)F36(x)=F12(x)F37(x)F37(x)=F18(x)+F35(x)F38(x)=F12(x)F39(x)F39(x)=F37(x)+F40(x)F40(x)=F41(x)+F44(x)F41(x)=F42(x)F42(x)=F12(x)F43(x)F43(x)=F18(x)+F41(x)F44(x)=F45(x)F45(x)=F12(x)F40(x)F46(x)=F32(x)+F47(x)+F74(x)F47(x)=F12(x)F48(x)F48(x)=F49(x)+F59(x)F49(x)=F10(x)+F50(x)F50(x)=F24(x)+F32(x)+F51(x)F51(x)=F12(x)F52(x)F52(x)=F53(x)+F56(x)F53(x)=F10(x)+F54(x)F54(x)=F55(x)F55(x)=F12(x)F53(x)F56(x)=F21(x)+F57(x)F57(x)=F58(x)F58(x)=F12(x)F56(x)F59(x)=F35(x)+F60(x)F60(x)=F32(x)+F61(x)+F66(x)+F71(x)F61(x)=F12(x)F62(x)F62(x)=F54(x)+F63(x)F63(x)=2F32(x)+F61(x)+F64(x)F64(x)=F12(x)F65(x)F65(x)=F35(x)+F63(x)F66(x)=F12(x)F67(x)F67(x)=F65(x)+F68(x)F68(x)=F44(x)+F69(x)F69(x)=F70(x)F70(x)=F12(x)F68(x)F71(x)=F12(x)F72(x)F72(x)=F31(x)+F73(x)F73(x)=F71(x)F74(x)=F12(x)F75(x)F75(x)=F76(x)+F79(x)F76(x)=F26(x)+F77(x)F77(x)=F32(x)+F47(x)+F78(x)F78(x)=F12(x)F76(x)F79(x)=F80(x)+F87(x)F80(x)=F32(x)+F38(x)+F81(x)F81(x)=F12(x)F82(x)F82(x)=F83(x)+F85(x)F83(x)=F10(x)+F84(x)F84(x)=F22(x)+F32(x)+F51(x)F85(x)=F35(x)+F86(x)F86(x)=F32(x)+F45(x)+F61(x)+F66(x)F87(x)=F88(x)F88(x)=F12(x)F79(x)