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A338976
Primes p such that p*A007953(p)+1 is prime.
2
2, 11, 13, 17, 19, 59, 71, 97, 107, 109, 149, 167, 181, 239, 271, 419, 431, 499, 509, 523, 547, 563, 613, 631, 691, 727, 811, 853, 859, 983, 1009, 1063, 1087, 1117, 1151, 1193, 1229, 1409, 1427, 1487, 1559, 1579, 1601, 1759, 1823, 1913, 1973, 2039, 2099, 2161, 2237, 2251, 2309, 2411, 2437, 2473
OFFSET
1,1
LINKS
EXAMPLE
a(3) = 13 is a term because 13 and 13*(1+3)+1 = 53 are prime.
MAPLE
select(t -> isprime(t) and isprime(t*convert(convert(t, base, 10), `+`)+1), [$2..10^4]);
PROG
(PARI) isok(p) = isprime(p) && isprime(p*sumdigits(p)+1); \\ Michel Marcus, Dec 18 2020
CROSSREFS
Subsequence of A119449.
Sequence in context: A296923 A243588 A137977 * A160950 A141168 A259394
KEYWORD
nonn,base
AUTHOR
J. M. Bergot and Robert Israel, Dec 18 2020
STATUS
approved