Number of 7-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
A209488
Number of 7-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
Terms
- a(0) =15a(1) =458a(2) =3740a(3) =17771a(4) =60778a(5) =168453a(6) =401634a(7) =857433a(8) =1679810a(9) =3074315a(10) =5321674a(11) =8796771a(12) =13984178a(13) =21501971a(14) =32119660a(15) =46785813a(16) =66648788a(17) =93089119a(18) =127741326a(19) =172532039a(20) =229703658a(21) =301856427a(22) =391974770a(23) =503474661a(24) =640230118a(25) =806627193
External references
- oeis: A209488