#The first, 60, terms of the sequence enumerating permutations of length n suc\
#    h that |pi[i+2]-pi[i]| is never 2 are

#Let's call it L22v


L22v:=
[1, 2, 4, 16, 44, 200, 1288, 9512, 78652, 744360, 7867148, 91310696, 1154292796
, 15784573160, 232050062524, 3648471927912, 61080818510972, 1084657970877416, 
20361216987032284, 402839381030339816, 8377409956454452732, 
182678001773062774632, 4167828820253946799580, 99292137525499869150056, 
2465527529988321926145148, 63704271555280621107183848, 
1710101405270323112159517916, 47626790016894277708127056872, 
1374305956375642411982698417148, 41037883377351622121202567287912, 
1266656031681902255259486481952476, 40368253747693813222893788235646568, 
1327068809196576138131488816314347644, 44958361170834617131818573462995145192,
1568218783559279355276983559478585123292, 
56275546603366536156862530625853889168104, 
2075906051934463458487571430948877408100860, 
78658776097348740121248803304518214696348008, 
3059369413718928625075757736090933559845948892, 
122059451848797913749566064058869188707358988648, 
4992174626394825743111097406998576087955918483580, 
209182133815847475214990526173417833980926528563944, 
8974825633879382646730932518480364915860814710235868, 
394054107141603159693206004119802639271667245874657768, 
17696474518799020225623125927957634894746964893140659196, 
812459056634410378153141115321689255180566169243691869800, 
38114680201319205519441064328444976275342854939233136697564, 
1826250004995165358408535602105293956309504435623650260014184, 
89333575671354139466000638906801288155330489944209716215350396, 
4459363877450709676909826924481773484224114171810116733493275624, 
227069758897966832724287434719752376936243037809301287485192366044, 
11789767756384420096485942935174459614887421006263937371638852016360, 
623948323992806239459959623988119753217234955757949449276406467283452, 
33645996128293820013864087793952736120282322813849426829016940394023784, 
1848031229864048037042304104170768312091317259608296333822189456792631260, 
103355021425349396640872395620161365428843187227092918784663890593210021736, 
5883836506043164561309239717298402553472434881131782247756272773274876488828, 
340848688075983756926986759725749736439651886741122515289797832800659892589800,
2008651478137251140580384052477353636228908842155500401268237166756304152991766\
0, 1203826235817093824339411879750506304804951288107054400198288735596918897330\
724840]:

#
#                      ---------------------------------
#                         This took, 5046.584, seconds.