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 A330424 a(1) = 1, a(2) = 2; thereafter a(n) = smallest number not occurring earlier such that both the sum of three successive terms and the sum of three successive digits are prime numbers. 2
 1, 2, 4, 5, 8, 6, 3, 20, 14, 25, 44, 34, 49, 68, 32, 27, 24, 10, 67, 60, 12, 29, 26, 52, 41065, 62, 50, 61, 40, 30, 43, 64, 72, 21, 46, 16, 41, 22, 38, 23, 28, 122, 7, 82, 18, 81, 2012, 218, 21021, 84, 58, 69, 2002, 90, 201, 106, 76, 47, 88, 128, 1223, 2038 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Lars Blomberg, Table of n, a(n) for n = 1..10000 EXAMPLE After 8 and 6 the next term is 3 as 8+6+3 = 17 is a prime; after 6 and 3 the next term is 20 as 6+3+20 = 29 and 6+3+2=11 are both primes; after 3 and 20 the next term is 14 as 3+20+14 = 37 and 3+2+0=5 are both primes; etc. CROSSREFS Cf. A076990 (only the sum of three successive terms is prime). Sequence in context: A352808 A076990 A330434 * A057168 A087711 A123128 Adjacent sequences: A330421 A330422 A330423 * A330425 A330426 A330427 KEYWORD base,nonn AUTHOR Eric Angelini and Lars Blomberg, Dec 14 2019 STATUS approved

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Last modified September 12 14:14 EDT 2024. Contains 375851 sequences. (Running on oeis4.)