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A048418
Primes whose consecutive digits differ by 6 or 7.
1
2, 3, 5, 7, 17, 29, 71, 181, 281, 293, 607, 829, 929, 2939, 3929, 8171, 8293, 9281, 9293, 18181, 28181, 39293, 60607, 70607, 70717, 71707, 81707, 81817, 82939, 170707, 171707, 181717, 182929, 281717, 392929, 393929, 607181, 707071, 718171
OFFSET
1,1
LINKS
MAPLE
extend:= proc(n) local d, x;
d:= n mod 10;
seq(10*n+x, x = select(t -> t >= 0 and t <= 9, [d-7, d-6, d+6, d+7]))
end proc:
R:= 2, 3, 5, 7: count:= 4:
T:= [$1..9]:
for d from 2 while count < 100 do
T:= map(extend, T);
V:= select(isprime, T);
count:= count+nops(V);
R:= R, op(V);
od:
R; # Robert Israel, Oct 17 2023
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Apr 15 1999
STATUS
approved