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A243974 Integers n not of form 3m+1 such that for any integer k>0, n*10^k-1 has a divisor in the set { 7, 11, 13, 37 }. 4
10176, 17601, 19361, 25827, 27147, 27686, 35916, 36048, 45462, 47213, 48036, 49248, 54638, 62864, 64184, 64899, 72953, 73085, 82499, 85073, 86285, 93435, 101760, 101936 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For n>24 a(n) = a(n-24) + 111111, the first 24 values are in the data.

If n is of form 3m+1 then n*10^k-1 is always divisible by 3. - Jens Kruse Andersen, Jul 09 2014

LINKS

Table of n, a(n) for n=1..24.

FORMULA

For n > 24, a(n) = a(n-24) + 111111.

EXAMPLE

10176*10^k-1 is divisible by 11 for k of form 6m, 6m+2, 6m+4, by 7 for k of form 6m+1, by 37 for 6m+3 (and also 6m), and by 13 for 6m+5. This covers all k. {7, 11, 13, 37} is called a covering set. - Jens Kruse Andersen, Jul 09 2014

PROG

(PFGW & SCRIPT)

SCRIPT

DIM k, 0

DIM n

DIMS t

OPENFILEOUT myf, res.txt

LABEL loop1

SET k, k+1

SET n, 0

LABEL loop2

SET n, n+1

IF n>500 THEN GOTO a

IF (k*10^n-1)%7==0 THEN GOTO loop2

IF (k*10^n-1)%11==0 THEN GOTO loop2

IF (k*10^n-1)%13==0 THEN GOTO loop2

IF (k*10^n-1)%37==0 THEN GOTO loop2

GOTO loop1

LABEL a

WRITE myf, k

PRINT k

GOTO loop1

CROSSREFS

Cf. A076337, A243969, A243974, A244070, A244071, A244072, A244073, A244074, A244076.

Sequence in context: A231030 A323486 A153139 * A251274 A184205 A128878

Adjacent sequences:  A243971 A243972 A243973 * A243975 A243976 A243977

KEYWORD

nonn

AUTHOR

Pierre CAMI, Jun 16 2014

EXTENSIONS

Definition corrected by Jens Kruse Andersen, Jul 09 2014

STATUS

approved

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Last modified April 16 17:01 EDT 2021. Contains 343050 sequences. (Running on oeis4.)