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URL: https://oeis.org/A381372

⇱ A381372 - OEIS


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A381372
Smaller of two consecutive primes p and q, both ending with 3, such that q-p = 10n, or -1 if no such primes exist.
2
283, 3413, 7253, 19333, 45893, 142993, 399283, 542603, 818723, 396733, 3240983, 10863973, 32788543, 8917523, 17652013, 92593183, 80935103, 92510963, 257789053, 481691513, 20831323, 47326693, 607010093, 1461724573, 387096133, 1496441363, 2298026803, 1855047163
OFFSET
1,1
EXAMPLE
a(1) = 283, because 283 and 283 + 10 = 293 are two consecutive primes with the same last digit 3 and no smaller p has this property.
PROG
(PARI) a(n) = my(p=3); while (!isprime(p) || ((nextprime(p+1)-p) != 10*n), p+=10); p; \\ Michel Marcus, Feb 24 2025
CROSSREFS
Sequence in context: A332676 A142837 A064964 * A372402 A263670 A108826
KEYWORD
nonn,base
AUTHOR
Jean-Marc Rebert, Feb 23 2025
STATUS
approved