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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A242622 a(n) = number of numbers with digit sum n, not greater than the n-th repunit (cf. A052222). 4

%I

%S 1,1,2,6,21,77,287,1079,4082,15522,59271,227131,873051,3364827,

%T 12998867,50321075,195162350,758156366,2949614789,11490869489,

%U 44819531180,175009397380,684059403670,2676260628574,10479320689274,41065736472890,161043272100440,631974335773536

%N a(n) = number of numbers with digit sum n, not greater than the n-th repunit (cf. A052222).

%C a(n) = length of row n in triangle A242614.

%H Jens Kruse Andersen, <a href="/A242622/b242622.txt">Table of n, a(n) for n = 0..100</a>

%o (Haskell)

%o a242622 = length . a242614_row

%o (PARI) \\ c[x,y] = #numbers < 10^x with digit sum y-1.

%o m=50; c=matrix(m,m+1); for(x=1, m, for(y=1, m+1, c[x,y]=sum(d=0, min(9,y-1), if(x>1, c[x-1,y-d], d==y-1)))); for(n=0, m, print1(1+sum(i=2, n, c[i-1,i+1])", ")); \\ _Jens Kruse Andersen_, Jul 17 2014

%K nonn,base

%O 0,3

%A _Reinhard Zumkeller_, Jul 16 2014

%E More terms from _Jens Kruse Andersen_, Jul 17 2014

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 February 19 04:00 EST 2020. Contains 332034 sequences. (Running on oeis4.)