cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A076489 Number of common (distinct) digits of consecutive natural numbers.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 2, 2, 2, 2, 2, 2
Offset: 0

Views

Author

Labos Elemer, Oct 21 2002

Keywords

Comments

a(A226637(n)) = 0. Reinhard Zumkeller, Sep 01 2013
This is the prefix overlap between the decimal expansions of n and n+1 (cf. A238845). - N. J. A. Sloane, Mar 22 2014

Crossrefs

Cf. A001477, A031298, A076490, A238845, A239092 (partial sums).

Programs

  • Haskell
    import Data.List (intersect, nub)
    a076489 n = a076489_list !! n
    a076489_list = map (length . nub) $
                   zipWith intersect (tail a031298_tabf) a031298_tabf
    -- Reinhard Zumkeller, Sep 01 2013
  • Mathematica
    Table[Length[Intersection[IntegerDigits[w], IntegerDigits[w+1]]], {w, 0, 200}]

Extensions

Initial zero prepended and offset adjusted by Reinhard Zumkeller, Sep 01 2013

A239091 Prefix overlap of dictionary consisting of binary expansions of 0 through n.

Original entry on oeis.org

0, 1, 2, 3, 5, 6, 8, 9, 12, 14, 17, 18, 21, 23, 26, 27, 31, 34, 38, 40, 44, 47, 51, 52, 56, 59, 63, 65, 69, 72, 76, 77, 82, 86, 91, 94, 99, 103, 108, 110, 115, 119, 124, 127, 132, 136, 141, 142, 147, 151, 156, 159, 164, 168, 173, 175, 180, 184, 189, 192, 197, 201, 206
Offset: 1

Views

Author

N. J. A. Sloane, Mar 22 2014

Keywords

Comments

The prefix overlap of a dictionary is the sum of the prefix overlaps between successive words.
Partial sums of A238845.

Examples

			For n=5 the dictionary is
0
1
10
11
100
101
and the successive prefix overlaps are 0,1,1,1,2, whose sum is a(5)=5.
		

Crossrefs

Formula

a(n) = A061168(n+1) - A011371(n+1) + A000523(n+1). - Alan Michael Gómez Calderón, Jul 17 2025
Showing 1-2 of 2 results.