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URL: https://oeis.org/A261200

⇱ A261200 - OEIS

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A261200
Minimal prime concatenation sequence with base 2 and seed 1.
4
1, 10, 101, 1011, 10111, 101111, 10111111, 101111111, 101111111011, 10111111101101, 101111111011010011, 10111111101101001101111, 10111111101101001101111101, 1011111110110100110111110101, 101111111011010011011111010111, 1011111110110100110111110101111
OFFSET
1,2
LINKS
EXAMPLE
In base 2, the least prime starting with seed 1 is 10; the least prime starting with 10 is 101; the least prime starting with 101 is 1011. Triangular format:
1
10
101
1011
10111
101111
10111111
101111111
101111111011
MATHEMATICA
b = 2; s = {{1}};
Do[NestWhile[# + 1 &, 0, ! (PrimeQ[FromDigits[tmp = Join[Last[s], (nn = #; IntegerDigits[nn - Sum[b^n, {n, l = NestWhile[# + 1 &, 1, ! (nn - (Sum[b^n, {n, #}]) < 0) &] - 1}], b, l + 1])], b]]) &];
AppendTo[s, tmp], {30}]; Map[FromDigits, s]
Map[FromDigits, s] (* A261200 *)
Map[FromDigits[#, b] &, s] (* A261201 *)
(* Peter J. C. Moses, Aug 06 2015 *)
CROSSREFS
A055011, A261200 and A261201 are all essentially the same sequence.
Sequence in context: A190480 A267623 A283508 * A175541 A180175 A267526
KEYWORD
nonn,easy,base
AUTHOR
Clark Kimberling, Sep 16 2015
STATUS
approved