login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A217446 Sum of the squares of numbers obtained by digit permutations of the concatenation of first n numbers. 1
1, 585, 331668, 213208980, 156226437720, 129158041750920, 119164964083502400, 121503028361696976960, 135757575541042424323200, 165013333307050666667644800, 216831999996550400000012812800, 306342399999513113600000180544000, 463124479999926454528000002723302400 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..100

FORMULA

a(n) = (1/12)*(n+1)!*(n*R'(n)+(3*n+2)*R(n)^2) with R(n) = (10^n-1)/9 and R'(n) = (10^(2*n)-1)/99.

EXAMPLE

a(1) = 1^2 = 1.

a(2) = 12^2 + 21^2 = 585.

a(3) = 123^2 + 132^2 + 213^2 + 231^2 + 312^2 + 321^2 = 331668.

MAPLE

R:= n-> (10^n-1)/9: RP:= n-> (10^(2*n)-1)/99:

a:= n-> (1/12)*(n+1)!*(n*RP(n)+(3*n+2)*R(n)^2):

seq (a(n), n=1..15);  # Alois P. Heinz, Oct 03 2012

CROSSREFS

Cf. A071268.

Sequence in context: A024380 A258331 A022243 * A171436 A020362 A051988

Adjacent sequences:  A217443 A217444 A217445 * A217447 A217448 A217449

KEYWORD

nonn,base

AUTHOR

Roger Cuculière, Oct 03 2012

EXTENSIONS

More terms from Alois P. Heinz, Oct 03 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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 3 02:14 EST 2021. Contains 349445 sequences. (Running on oeis4.)