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 A033680 a(1) = 1; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime. 17
 1, 1, 3, 11, 13, 29, 39, 49, 83, 141, 247, 273, 291, 347, 373, 401, 441, 567, 571, 651, 903, 957, 1001, 1129, 1401, 1457, 1467, 1561, 1889, 2083, 2169, 2523, 2717, 2743, 3447, 3509, 3711, 4087, 4899, 4983, 5087, 5151, 5263, 5429, 5551, 6017, 7389, 7839 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Giovanni Resta, Table of n, a(n) for n = 1..800 MATHEMATICA a[1] = 1; a[n_] := a[n] = Block[{k = a[n - 1], 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 *) nxt[{c_, a_}]:=Module[{x=a}, While[!PrimeQ[FromDigits[Join[c, IntegerDigits[ x]]]], x+=2]; {Join[c, IntegerDigits[x]], x}]; NestList[nxt, {{1}, 1}, 50][[All, 2]] (* Harvey P. Dale, Sep 14 2018 *) CROSSREFS Cf. A074336, A092528, A069602, A033679, A033681, A046254, A046255, A046256, A046257, A046258, A046259, A111524. Sequence in context: A213697 A287348 A019374 * A032917 A006559 A023248 Adjacent sequences:  A033677 A033678 A033679 * A033681 A033682 A033683 KEYWORD nonn,nice AUTHOR EXTENSIONS More terms from Patrick De Geest, May 15 1998 More terms from Robert G. Wilson v, Aug 05 2005 STATUS approved

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Last modified January 26 13:09 EST 2022. Contains 350598 sequences. (Running on oeis4.)