A074343 - OEIS

A074343

a(1) = 7; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.

7, 9, 19, 27, 47, 57, 61, 81, 179, 211, 251, 273, 373, 477, 581, 753, 847, 909, 971, 1399, 1623, 1967, 2139, 2629, 2979, 3297, 3393, 3647, 3793, 4281, 4337, 4411, 4517, 4831, 4979, 5131, 5841, 5897, 5953, 5991, 6287, 6309, 8101, 8147, 8521, 8877, 8969, 9699

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..48.

MATHEMATICA

a[1] = 7; a[n_] := a[n] = Block[{k = a[n - 1] + 1 + Mod[a[n - 1], 2], c = IntegerDigits @ Table[ a[i], {i, n - 1}]}, While[ !PrimeQ[ FromDigits @ Flatten @ Append[c, IntegerDigits[k]]], k += 2]; k]; Table[ a[n], {n, 48}] (* Robert G. Wilson v *)

CROSSREFS

Cf. A046257, A069609, A074336, A074338, A074339, A074340, A074341, A074342, A074344, A074345, A074346.

Sequence in context: A320323 A032791 A046257 * A103853 A192160 A139202

Adjacent sequences: A074340 A074341 A074342 * A074344 A074345 A074346

KEYWORD

nonn,base

AUTHOR

Zak Seidov, Sep 23 2002

EXTENSIONS

More terms from Robert G. Wilson v, Aug 05 2005

STATUS

approved