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A340634
Numbers k such that k + A037276(k) is prime.
3
1, 6, 14, 18, 22, 26, 34, 36, 38, 46, 48, 62, 66, 74, 106, 108, 110, 122, 134, 146, 156, 166, 170, 174, 178, 194, 196, 198, 206, 226, 230, 254, 262, 274, 278, 290, 294, 298, 306, 318, 354, 362, 374, 386, 392, 394, 416, 420, 422, 426, 458, 466, 468, 490, 502, 504, 516, 526, 528, 530, 532, 544, 562
OFFSET
1,2
COMMENTS
All terms except 1 are even.
LINKS
EXAMPLE
a(3) = 14 is a term because 14 + A037276(14) = 14 + 27 = 41 is prime.
MAPLE
dcat:= proc(L) local i, x;
x:= L[-1];
for i from nops(L)-1 to 1 by -1 do
x:= 10^(1+ilog10(x))*L[i]+x
od;
x
end proc:
A037276:= proc(n) local F;
F:= sort(ifactors(n)[2], (a, b) -> a[1] < b[1]);
dcat(map(t -> t[1]$t[2], F));
end proc:
A037276(1):= 1:
select(t -> isprime(t + A037276(t)), [1, seq(i, i=3..1000)]);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
J. M. Bergot and Robert Israel, Jan 14 2021
STATUS
approved