|
Search: id:A060072
|
|
|
| A060072 |
|
a(n) = (n^(n-1)-1)/(n-1). |
|
+0
10
|
|
| 0, 1, 4, 21, 156, 1555, 19608, 299593, 5380840, 111111111, 2593742460, 67546215517, 1941507093540, 61054982558011, 2085209001813616, 76861433640456465, 3041324492229179280, 128583032925805678351
(list; graph; listen)
|
|
|
OFFSET
|
1,3
|
|
|
COMMENT
|
(n-1)-digit repunits in base n written in decimal.
|
|
LINKS
|
Harry J. Smith, Table of n, a(n) for n=1,...,200
|
|
FORMULA
|
a(n) = sum( n^(k-1) C(n, k) ), k=1..n - Olivier Gerard (olivier.gerard(AT)gmail.com), Jun 26 2001
sum (n^(n-j),j=2..n). - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Sep 11 2006
a(n+1) = A125118(n,n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 21 2006
|
|
EXAMPLE
|
a(10)=111111111; i.e. just nine 1's (converted from base 10 to decimal)
|
|
MAPLE
|
a:=n->sum ((n+2)^j, j=0..n): seq(a(n), n=-1..17); # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 17 2008]
|
|
PROGRAM
|
(PARI) { write("b060072.txt", "1 0"); for (n=2, 200, write("b060072.txt", n, " ", (n^(n - 1) - 1)/(n - 1)); ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jul 01 2009]
|
|
CROSSREFS
|
a(n) = A060071(n)/(n-1) = A060073(n)*(n-1) = A023037(n)-A000169(n)
Cf. A055869.
Sequence in context: A163861 A006153 A025164 this_sequence A157503 A144010 A107872
Adjacent sequences: A060069 A060070 A060071 this_sequence A060073 A060074 A060075
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Henry Bottomley (se16(AT)btinternet.com), Feb 21 2001
|
|
|
Search completed in 0.002 seconds
|
