OFFSET
1,1
REFERENCES
F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Ars Combin. 49 (1998), 129-154.
LINKS
Sean A. Irvine, Table of n, a(n) for n = 1..100
F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Preliminary version of paper that appeared in Ars Combin. 49 (1998), 129-154.
F. Faase, Results from the counting program
FORMULA
a(1) = 36,
a(2) = 3960,
a(3) = 197172,
a(4) = 8372376,
a(5) = 313590732,
a(6) = 10961493288,
a(7) = 364496212992,
a(8) = 11715923002644,
a(9) = 367218115613412,
a(10) = 11297962590845364,
a(11) = 342721436917704060,
a(12) = 10284809936813182116,
a(13) = 306078425919342660924,
a(14) = 9050314137435866812308,
a(15) = 266262758895847900204044,
a(16) = 7802857128214786920966468,
a(17) = 227964188131745757879553596,
a(18) = 6644168196971243295712163700,
a(19) = 193287318120848681996183075244,
a(20) = 5614785173559337471057013732388,
a(21) = 162918194408431653609336890189340,
a(22) = 4723043996602440520832973512325972,
a(23) = 136828273928341927052870400623002380, and
a(n) = 59a(n-1) - 731a(n-2) - 11403a(n-3) + 204688a(n-4) + 697232a(n-5)
- 13575824a(n-6) + 15466532a(n-7) + 288258520a(n-8) - 1327022000a(n-9) + 1631290560a(n-10)
+ 3212771840a(n-11) - 12023726208a(n-12) + 9649896000a(n-13) + 11298643072a(n-14) - 24109594624a(n-15)
+ 6239014400a(n-16) + 14028280832a(n-17) - 8564428800a(n-18) - 2763866112a(n-19) + 2175729664a(n-20)
+ 199229440a(n-21) - 150994944a(n-22).
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Added recurrence from Faase's web page. - N. J. A. Sloane, Feb 03 2009
STATUS
approved