|
|
|
|
405, 412, 850, 25315, 49419, 50127, 224315, 293394, 308700, 697136, 801350, 811910, 997425, 1118520, 1152000, 1177250, 1550520, 1659350, 1725332, 1739640, 1824500, 1976895, 2141150, 2580640, 2580831, 3530466, 3718376, 4050405, 4459455, 4536532, 4577732, 4832796, 5173100, 5510287, 5601570, 5603989, 5609439
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
EXAMPLE
|
a(3)=850 is in the sequence because A001414(850)=2+5+5+17=29, A001414(58)=2+29=31, and (29,31) is a pair of twin primes.
|
|
MAPLE
|
revdigs:= proc(n) local L, k;
L:= convert(n, base, 10);
add(L[-k]*10^(k-1), k=1..nops(L))
end proc:
filter:= proc(n) local a, b;
a:= convert(map(convert, ifactors(n)[2], `*`), `+`);
if not isprime(a) then return false fi;
b:= convert(map(convert, ifactors(revdigs(n))[2], `*`), `+`);
b = a+2 and isprime(b)
end proc:
select(filter, [$1 .. 10^7]);
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|