A002782 - OEIS

A002782

Concatenate the natural numbers, then partition into minimal strings so that each term divides the next.
(Formerly M2157 N0859)

1, 2, 34, 5678, 9101112131415161718192021222324252627282930313233343536

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

What is the next term? (See A263623.)

a(6), if it exists, has more than 5888833 digits. - Lars Blomberg, Dec 01 2016

REFERENCES

Letter from the editor, J. Rec. Math., 3 (1970), 40-41.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Editor, J. Recreational Math., Letter, J. Rec. Math., 3 (1970), 40-41. [Annotated scanned copy]

EXAMPLE

1 divides 2 divides 34 divides 5678 divides 9101112131415161718192021222324252627282930313233343536.

PROG

(Haskell)

a002782 n = a002782_list !! (n-1)

a002782_list = f 1 1 (map toInteger $ tail a007376_list) where

f x y (d:ds) | mod y x == 0 = y : f y d ds

| otherwise = f x (10*y + d) ds

CROSSREFS

See A007908 for a classic sequence of the same ilk.

KEYWORD

nonn,base,nice

AUTHOR

STATUS

approved