A259528 n-th number with exactly n n's in base 10.

1, 122, 2333, 34444, 455555, 5666666, 67777777, 788888888, 8999999999, 101010101010101010010, 11111111110111111111111, 1212121121212121212121212, 131313013131313131313131313, 14141241414141414141414141414

Offset: 1

Author

Jonathan Vos Post, Jun 29 2015

Keywords

• nonn
• base
• easy

Comments

Main diagonal M[n,n,n] of M[i,j,k] = k-th natural number such that number of i's in base 10 is j, for i,j,k = 1,2,3,4,5,....

M[1,1,n] = A043493 Numbers that contain a single 1.

M[2,2,n] = A043498 Numbers n such that number of 2's in base 10 is 2.

M[3,3,n] = A043503 Numbers n such that number of 3's in base 10 is 3.

M[4,4,n] = A043508 Numbers n such that number of 4's in base 10 is 4.

Examples

			First element is 1, the 1st natural number with exactly one 1 in base 10.
Second element is 122, the 2nd natural number with exactly two 2's in base 10.
Third element is 2333, the 3rd natural number with exactly three 3's in base 10.
		

Crossrefs

Cf. A043493, A043498, A043503, A043508.

Programs

PARI

a(n)=my(v=List(),k=10^#Str(n),d=List(digits((k^n-1)/(k-1)*n)),t); for(i=1,#d+1, t=d; listinsert(t,0,i); t=Vec(t); for(j=0,9, t[i]=j; listput(v,fromdigits(t)))); Set(v)[n] \\ Charles R Greathouse IV, Jun 29 2015

Extensions

a(5)-a(14) from Charles R Greathouse IV, Jun 29 2015