Recurrence from Faase web site:
a(1) = 1,
a(2) = 34,
a(3) = 153,
a(4) = 2245,
a(5) = 14824,
a(6) = 167089,
a(7) = 1292697,
a(8) = 12988816,
a(9) = 108435745,
a(10) = 1031151241,
a(11) = 8940739824,
a(12) = 82741005829,
a(13) = 731164253833,
a(14) = 6675498237130,
a(15) = 59554200469113,
a(16) = 540061286536921,
a(17) = 4841110033666048,
a(18) = 43752732573098281,
a(19) = 393139145126822985,
a(20) = 3547073578562247994,
a(21) = 31910388243436817641,
a(22) = 287665106926232833093,
a(23) = 2589464895903294456096,
a(24) = 23333526083922816720025,
a(25) = 210103825878043857266833,
a(26) = 1892830605678515060701072,
a(27) = 17046328120997609883612969,
a(28) = 153554399246902845860302369,
a(29) = 1382974514097522648618420280,
a(30) = 12457255314954679645007780869,
a(31) = 112199448394764215277422176953,
a(32) = 1010618564986361239515088848178, and
a(n) = 153a(n-2) - 7480a(n-4) + 151623a(n-6) - 1552087a(n-8) + 8933976a(n-10) - 30536233a(n-12) + 63544113a(n-14) - 81114784a(n-16) + 63544113a(n-18) - 30536233a(n-20) + 8933976a(n-22) - 1552087a(n-24) + 151623a(n-26) - 7480a(n-28) + 153a(n-30) - a(n-32).
G.f.: (1 -43*x^2 -26*x^3 +360*x^4 +110*x^5 -1033*x^6 +1033*x^8 -110*x^9 -360*x^10 +26*x^11 +43*x^12 -x^14) /(1 -x -76*x^2 -69*x^3 +921*x^4 +584*x^5 -4019*x^6 -829*x^7 +7012*x^8 -829*x^9 -4019*x^10 +584*x^11 +921*x^12 -69*x^13 -76*x^14 -x^15 +x^16). -
Sergey Perepechko, Nov 22 2012
