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 A090195 Primes which when multiplied by their largest digit and 1 is subtracted form another prime. 1
 2, 41, 163, 181, 211, 431, 463, 613, 653, 853, 1163, 1381, 1483, 1613, 1801, 1861, 1873, 2011, 2063, 2141, 2221, 2243, 2411, 2633, 2851, 3041, 3181, 3583, 3623, 4211, 4241, 4363, 4421, 4463, 4483, 4603, 5563, 5581, 5821, 5851, 6113, 6143, 6203, 6553 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 FORMULA In the prime sequence, select largest digit in each prime, multiply by the prime containing that digit, then subtract 1. If the result is another prime, add to sequence. EXAMPLE a(2)=41. Largest digit is 4. Multiply 41*4=164. 164-1=163, prime. MATHEMATICA Select[Prime[Range[1000]], PrimeQ[# Max[IntegerDigits[#]]-1]&] (* Harvey P. Dale, Dec 31 2019 *) PROG (PARI) isok(p) = isprime(p) && isprime(p*vecmax(digits(p))-1); \\ Michel Marcus, Jun 08 2014 CROSSREFS Cf. A060418. Sequence in context: A047936 A007533 A088565 * A287335 A212837 A063271 Adjacent sequences:  A090192 A090193 A090194 * A090196 A090197 A090198 KEYWORD easy,nonn,base AUTHOR Enoch Haga, Jan 22 2004 STATUS approved

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Last modified May 9 10:39 EDT 2021. Contains 343732 sequences. (Running on oeis4.)