Number of solutions to Langford (or Langford-Skolem) problem (up to reversal of the order).
A014552
Number of solutions to Langford (or Langford-Skolem) problem (up to reversal of the order).
Terms
- a(0) =0a(1) =0a(2) =1a(3) =1a(4) =0a(5) =0a(6) =26a(7) =150a(8) =0a(9) =0a(10) =17792a(11) =108144a(12) =0a(13) =0a(14) =39809640a(15) =326721800a(16) =0a(17) =0a(18) =256814891280a(20) =0a(21) =0a(24) =0a(25) =0a(28) =0a(29) =0
External references
- oeis: A014552