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A287304 Primes that can be generated by the concatenation in base 5, in ascending order, of two consecutive integers read in base 10. 0
7, 13, 19, 131, 157, 313, 443, 521, 547, 599, 3529, 3907, 4159, 4663, 4789, 5167, 5419, 5923, 6301, 6427, 6553, 6679, 7057, 7309, 7561, 7687, 8191, 8317, 8443, 8821, 9199, 9829, 10333, 10459, 10711, 10837, 11467, 11593, 11719, 11971, 12097, 12601, 12853, 12979 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..44.

EXAMPLE

1 and 2 in base 5 are 1 and 2 and concat(1,2) = 12 in base 10 is 7;

6 and 7 in base 5 are 11 and 12 and concat(11,12) = 1112 in base 10 is 157.

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, 5), i=1..1000);

MATHEMATICA

With[{b = 5}, Select[Map[FromDigits[Flatten@ IntegerDigits[#, b], b] &, Partition[Range@ 120, 2, 1]], PrimeQ]] (* Michael De Vlieger, May 23 2017 *)

Select[FromDigits[Flatten[#], 5]&/@Partition[IntegerDigits[Range[150], 5], 2, 1], PrimeQ] (* Harvey P. Dale, Nov 25 2020 *)

CROSSREFS

Cf. A000040, A030458.

Sequence in context: A355329 A133029 A243962 * A023984 A308200 A126621

Adjacent sequences: A287301 A287302 A287303 * A287305 A287306 A287307

KEYWORD

nonn,base,easy

AUTHOR

Paolo P. Lava, May 23 2017

STATUS

approved

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Last modified December 7 13:02 EST 2022. Contains 358656 sequences. (Running on oeis4.)