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A287312 Primes that can be generated by the concatenation in base 9, in ascending order, of two consecutive integers read in base 10. 0
11, 31, 41, 61, 71, 739, 821, 1231, 1559, 1723, 2297, 2543, 2707, 2789, 2953, 3527, 3691, 4019, 5003, 5167, 5413, 5659, 5741, 5987, 6151, 6397, 65701, 66431, 67891, 72271, 76651, 81031, 81761, 83221, 85411, 100741, 102931, 108041, 121181, 135781, 136511, 140891 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
1 and 2 in base 9 are 1 and 2 and concat(1,2) = 12 in base 10 is 11;
9 and 10 in base 9 are 10 and 11 and concat(10,11) = 1011 in base 10 is 739.
MAPLE
with(numtheory): P:= proc(q, h) local a, b, c, d, k, n; a:=convert(q+1, base, h); b:=convert(q, base, h); c:=[op(a), op(b)]; d:=0; for k from nops(c) by -1 to 1 do d:=h*d+c[k]; od; if isprime(d) then d; fi; end: seq(P(i, 9), i=1..1000);
MATHEMATICA
With[{b = 9}, Select[Map[FromDigits[Flatten@ IntegerDigits[#, b], b] &, Partition[Range@ 200, 2, 1]], PrimeQ]] (* Michael De Vlieger, May 25 2017 *)
CROSSREFS
Sequence in context: A040979 A181182 A089347 * A240896 A040985 A061599
KEYWORD
nonn,base,easy
AUTHOR
Paolo P. Lava, May 24 2017
STATUS
approved

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Last modified February 27 16:21 EST 2024. Contains 370378 sequences. (Running on oeis4.)