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A337190
Numbers k such that A337183(k) and k + A337183(k) are prime.
1
6, 10, 22, 42, 68, 102, 106, 116, 126, 168, 170, 178, 186, 202, 230, 242, 262, 356, 366, 436, 480, 502, 506, 516, 610, 622, 630, 638, 668, 696, 716, 778, 788, 798, 868, 890, 990, 1018, 1034, 1042, 1070, 1108, 1126, 1166, 1186, 1198, 1206, 1228, 1264, 1268, 1350, 1388, 1446, 1614, 1650, 1682, 1690
OFFSET
1,1
COMMENTS
All terms are even.
LINKS
EXAMPLE
a(3) = 22 is a member because A337183(22) = 37 and 37+22 = 59 are both prime.
MAPLE
f:= proc(n) local F, b, i;
F:= sort(map(t -> t[1]$t[2], ifactors(n)[2]), `>`);
b:= convert(F, `+`);
(add(F[i]*b^(i-1), i=1..nops(F)));
end proc:
filter:= proc(n) local v;
v:= f(n); isprime(v) and isprime(v+n)
end proc:
select(filter, 2*[$1..1000]);
MATHEMATICA
Select[Range[2, 1690], AllTrue[If[PrimeQ@ #, #, FromDigits[#, Total[#]] &@ Flatten[ConstantArray @@@ FactorInteger[#]]] + {0, #}, PrimeQ] &] (* Michael De Vlieger, Jan 29 2021 *)
CROSSREFS
Cf. A337183. Contained in A337185.
Sequence in context: A216049 A063765 A085712 * A179875 A166305 A047651
KEYWORD
nonn,base
AUTHOR
J. M. Bergot and Robert Israel, Jan 29 2021
STATUS
approved