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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A104620 Consider the presentation of the digits of the natural numbers in a triangular form for successive bases, b. Now examine the main diagonal of these triangles and note the first occurrence of the n digits (0 through b-1). This is its own triangle presented here. 15
1, 2, 1, 4, 1, 9, 6, 1, 8, 2, 3, 1, 4, 2, 19, 10, 1, 7, 2, 5, 31, 8, 1, 6, 2, 10, 18, 3, 14, 1, 7, 2, 11, 12, 3, 10, 4, 1, 29, 2, 8, 13, 3, 12, 62, 13, 1, 5, 2, 12, 6, 3, 9, 23, 73, 12, 1, 9, 2, 13, 11, 3, 16, 7, 80, 4, 22, 1, 8, 2, 6, 15, 3, 18, 19, 10, 4, 37, 11, 1, 9, 2, 13, 70, 3, 7, 26, 16 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See A104606 through A104613, A091425, A104614 through A104619 as examples in the OEIS data base for triangular forms to base n>1.

t(n,2)=1, t(n,4)=2, t(n,7)=3, t(n,11)=4, t(n,16)=5 and t(n,1+i(i+1)/2)=i.

LINKS

Table of n, a(n) for n=1..88.

EXAMPLE

Triangle begins:

1

2 1

4 1 9

6 1 8 2

3 1 4 2 19

10 1 7 2 5 31

MATHEMATICA

f[n_] := If[n == 1, 0, Block[{t = Flatten[ IntegerDigits[ Range[ 2000], n]]}, u = t[[ Table[ i(i + 1)/2, {i, 100}]]]; Table[ Position[u, i, 1, 1], {i, 0, n - 1}]]]; Flatten[ Table[ f[n], {n, 13}]]

CROSSREFS

Cf. A104606, A104607, A104608, A104609, A104610, A104611, A104612, A104613, A091425, A104614, A104615, A104616, A104617, A104618, A104619.

Sequence in context: A147080 A146418 A146011 * A243913 A186724 A145930

Adjacent sequences:  A104617 A104618 A104619 * A104621 A104622 A104623

KEYWORD

base,nonn,tabl

AUTHOR

Robert G. Wilson v, Mar 17 2005

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 January 20 23:29 EST 2020. Contains 331104 sequences. (Running on oeis4.)