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 A321337 a(n) is the least number with n factorizations into S-primes (numbers 4k+1 with no proper divisors > 1 of form 4m+1). 1
 1, 441, 4389, 39501, 53361, 92169, 829521, 1935549, 302841, 2725569, 3041577, 27374193, 853577109, 7682193981, 3129357, 6359661, 19263321, 234201429, 230639102001, 437200389130923862144165773, 1341335457, 12072019113, 23318757, 1201975929, 28164213, 253477917, 4918230009, 101711843982441 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS It suffices to check only numbers with all prime factors congruent to 3 mod 4 and continuous, nonincreasing prime exponents (i.e., members of the analog of A025487 with respect to primes congruent to 3 mod 4). LINKS Charlie Neder, Table of n, a(n) for n = 1..277 Charlie Neder, Table of n, a(n) for n = 1..600, missing 278 and 482 EXAMPLE a(4) = 39501 can be factored into S-primes (A057948) in 4 distinct ways: 9 * 21 * 209, 9 * 33 * 133, 9 * 57 * 77, or 21 * 33 * 57, and it is the smallest number with this property. CROSSREFS Cf. A054520, A057948 (S-primes), A057949 (numbers with multiple factorizations into S-primes). Sequence in context: A202400 A014793 A264305 * A206467 A264262 A232003 Adjacent sequences: A321334 A321335 A321336 * A321338 A321339 A321340 KEYWORD nonn AUTHOR Charlie Neder, Nov 05 2018 EXTENSIONS a(13) corrected by David A. Corneth, Nov 10 2018 More terms from WG Zeist, Jan 09 2019 STATUS approved

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Last modified March 2 20:41 EST 2024. Contains 370498 sequences. (Running on oeis4.)