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A261672
Numbers k such that A037610(k) is prime.
0
4, 7, 52, 100, 136, 388, 30940, 33250
OFFSET
1,1
COMMENTS
The terms are a subset of the terms of A016777, since a term of A037610 can only be prime if it is congruent to 1 modulo 10 and hence congruent to 1 modulo 3. If A037610(k) is congruent to 1 modulo 3, then k is congruent to 1 modulo 3 as well.
No further terms up to 10000.
EXAMPLE
A037610(7) = 1231231 is prime, so 7 is a term of the sequence.
MATHEMATICA
Select[Range@ 500, PrimeQ@ Floor[41/333*10^#] &] (* Michael De Vlieger, Sep 07 2015 *)
PROG
(PARI) a037610(n) = 10^n*41\333
is(n) = ispseudoprime(a037610(n))
CROSSREFS
Sequence in context: A249936 A049191 A308463 * A013467 A330450 A060413
KEYWORD
nonn,more
AUTHOR
Felix Fröhlich, Sep 04 2015
EXTENSIONS
a(7)-a(8) from Michael S. Branicky, Jun 28 2023
STATUS
approved