This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A217675 Number of permutations in S_n containing an increasing subsequence of length 8. 3
 1, 65, 2603, 83923, 2410291, 64864819, 1683724308, 42918747000, 1086997811325, 27571922195325, 704311698875426, 18189847735254134, 476311846323448840, 12672229166094171240, 343069245941729668380, 9461927811882316662636, 266091066751920438364275 (list; graph; refs; listen; history; text; internal format)
 OFFSET 8,2 LINKS Alois P. Heinz, Table of n, a(n) for n = 8..200 FORMULA a(n) = A214152(n,8) = A000142(n)-A072131(n) = A000142(n)-A214015(n,7). EXAMPLE a(8) = 1: 12345678. MAPLE b:= proc(n) option remember; `if`(n<8, n!, ((-343035+429858*n        +238440*n^3+38958*n^4+634756*n^2+2940*n^5+84*n^6)*b(n-1)        -(1974*n^4+36336*n^3+213240*n^2+407840*n+82425)*(n-1)^2*b(n-2)        +2*(49875+42646*n+6458*n^2)*(n-1)^2*(n-2)^2*b(n-3)        -11025*(n-1)^2*(n-2)^2*(n-3)^2*b(n-4))/ ((n+6)^2*(n+10)^2*(n+12)^2))     end: a:= n-> n! -b(n): seq(a(n), n=8..25); CROSSREFS Cf. A000142, A072131, A214015, A214152. Sequence in context: A300168 A004354 A016111 * A237858 A075474 A069225 Adjacent sequences:  A217672 A217673 A217674 * A217676 A217677 A217678 KEYWORD nonn AUTHOR Alois P. Heinz, Oct 10 2012 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 6 18:03 EST 2019. Contains 329809 sequences. (Running on oeis4.)