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A225613 The largest n-digit number whose first k digits are divisible by the k-th prime for k = 1..n. 1
8, 87, 875, 8757, 87571, 875719, 8757193, 87571931, 875719319, 8757193191 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

There are 10 terms in the series; the 10-digit number 8757193191 is the largest number to satisfy the requirements.

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

There are four one-digit numbers divisible by the first prime (2) and the largest is 8, so a(1)=8.

For two-digit numbers, the second digit must make it divisible by 3, which gives 87 as the largest to satisfy the requirement, so a(2)=87.

MATHEMATICA

a=Table[j, {j, 2, 8, 2}]; r=2; t={}; While[!a == {}, n=Length[a]; nmax=Last[a]; k=1; b={}; While[!k>n, z0=a[[k]]; Do[z=10*z0+j; If[Mod[z, Prime[r]]==0, b=Append[b, z]], {j, 0, 9}]; k++]; AppendTo[t, nmax]; a=b; r++]; t

CROSSREFS

Subsequence of A079206.

Cf. A143867, A225614.

Sequence in context: A200767 A222513 A307822 * A243922 A239753 A246512

Adjacent sequences:  A225610 A225611 A225612 * A225614 A225615 A225616

KEYWORD

nonn,base,fini,full

AUTHOR

Shyam Sunder Gupta, Aug 04 2013

STATUS

approved

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Last modified October 26 05:32 EDT 2021. Contains 348256 sequences. (Running on oeis4.)