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A072125 Concatenation of first n entries (digits) of A007376 is not divisible by 3. 1
1, 4, 7, 10, 11, 12, 14, 16, 17, 18, 20, 22, 23, 24, 26, 28, 29, 32, 34, 35, 38, 40, 41, 44, 46, 47, 53, 54, 59, 60, 65, 66, 70, 71, 72, 74, 76, 77, 78, 80, 82, 83, 84, 86, 88, 89, 92, 94, 95, 98, 100, 101, 104, 106, 107, 113, 114, 119, 120, 125, 126, 130, 131, 132, 134 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Concatenation of some permutations of the n digits of A007376 is likely to be prime.

LINKS

Table of n, a(n) for n=1..65.

EXAMPLE

16 is in the sequence because the 16-digit number 1234567891011121 = 1 (mod 3).

MATHEMATICA

f[0] = 0; f[n_Integer] := 10^(Floor[Log[10, n]] + 1)*f[n - 1] + n; Select[ Range[140], Mod[ FromDigits[ Take[ IntegerDigits[ f[n]], n]], 3] != 0 &]

CROSSREFS

Cf. A007376 & A033307.

Sequence in context: A282848 A093465 A123869 * A223024 A275340 A082206

Adjacent sequences:  A072122 A072123 A072124 * A072126 A072127 A072128

KEYWORD

easy,nonn,base

AUTHOR

Lekraj Beedassy, Jun 20 2002

EXTENSIONS

Edited by Robert G. Wilson v, Jun 21 2002

STATUS

approved

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Last modified November 14 15:27 EST 2018. Contains 317208 sequences. (Running on oeis4.)