|
| |
|
|
A072856
|
|
Number of permutations satisfying i-4<=p(i)<=i+4, i=1..n (permutations of length n within distance 4).
|
|
68
| |
|
|
1, 2, 6, 24, 120, 504, 1902, 6902, 25231, 95401, 365116, 1396948, 5316192, 20135712, 76227216, 288878956, 1095937420, 4159450913, 15783649241, 59878012558, 227128287882, 861543171080, 3268198646496, 12398132725784
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| a(n) equals the permanent of the nXn matrix with 1's along the nine central diagonals and 0's everywhere else. [From John M. Campbell, Jul 09 2011]
|
|
|
LINKS
| R. H. Hardin, Table of n, a(n) for n=1..400, Jul 11 2010
Torleiv Klove, Spheres of Permutations under the Infinity Norm - Permutations with limited displacement. Reports in Informatics, Department of Informatics, University of Bergen, Norway, no. 376, November 2008.
|
|
|
FORMULA
| Gf.: (1 - 2x - 3*x^2 - *x^3 + 4*x^4 - 31*x^5 - 5*x^6 + 32*x^7 - 21*x^8 + 129*x^9 + 94*x^10 - 83*x^11 + 11*x^12 - 192*x^13 - 59*x^14 + 63*x^15 - 16*x^16 + 3*x^17 - 29*x^18 - 46*x^19 - 57*x^20 + 253*x^21 - 28*x^22 - 101*x^23 + 17*x^24 + 104*x^25 - 15*x^26 - 29*x^27 + 10*x^28 - *x^29 + *x^30 - *x^32 - 3*x^33 + x^35)/
(1 - 3x - 2*x^2 + *x^3 + *x^4 - 70*x^5 - 39*x^6 + 31*x^7 + 114*x^8 + 522*x^9 + 184*x^10 - 34*x^11 - 46*x^12 - 1444*x^13 - 202*x^14 + 606*x^15 - 1204*x^16 - 198*x^17 + 804*x^18 - 542*x^19 + 26*x^20 + 2372*x^21 + 318*x^22 - 1582*x^23 + 328*x^24 + 2018*x^25 + 222*x^26 - 810*x^27 - 184*x^28 + 706*x^29 + 14*x^30 - 204*x^31 - 70*x^32 - 14*x^33 - 28*x^34 + 22*x^35 + 11*x^36 - 47*x^37 + 8*x^38 + 11*x^39 + *x^40 + 4*x^41 - x^42 - x^43) [From Torleiv Klove (Torleiv.Klove(AT)ii.uib.no), Jan 13 2009]
|
|
|
CROSSREFS
| Cf. A002524..A002529, A072827.
Sequence in context: A174701 A178848 A173845 * A189861 A189570 A179340
Adjacent sequences: A072853 A072854 A072855 * A072857 A072858 A072859
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Vladimir Baltic (baltic(AT)matf.bg.ac.yu), Jul 25 2002
|
| |
|
|
