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A287310 Primes that can be generated by the concatenation in base 8, in ascending order, of two consecutive integers read in base 10. 2
19, 37, 521, 911, 1171, 1301, 1951, 2081, 2341, 2731, 2861, 3121, 3251, 3511, 32833, 35911, 37963, 43093, 44119, 46171, 53353, 56431, 57457, 59509, 61561, 68743, 71821, 77977, 85159, 87211, 88237, 90289, 95419, 99523, 100549, 114913, 117991, 123121, 124147, 126199 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Primes of the form (1+8^k) m + 1 where m+1 < 8^k < 8(m+1). - Robert Israel, May 24 2017
LINKS
EXAMPLE
2 and 3 in base 8 are 2_8 and 3_8, and concat(2,3) = 23_8 in base 10 is 19;
8 and 9 in base 8 are 10_8 and 11_8 and concat(10,11) = 1011_8 in base 10 is 521.
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, 8), i=1..1000);
MATHEMATICA
With[{b = 8}, Select[Map[FromDigits[Flatten@ IntegerDigits[#, b], b] &, Partition[Range@ 250, 2, 1]], PrimeQ]] (* Michael De Vlieger, May 25 2017 *)
CROSSREFS
Sequence in context: A350469 A111441 A144594 * A123028 A067205 A196185
KEYWORD
nonn,base,easy
AUTHOR
Paolo P. Lava, May 24 2017
STATUS
approved

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Last modified March 28 05:39 EDT 2024. Contains 371235 sequences. (Running on oeis4.)