17989

Properties

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 3.at n=38A013643
• a(n) = 11*a(n-1) + 9*a(n-2).at n=5A015603
• Primes that remain prime through 3 iterations of function f(x) = 2x + 5.at n=42A023274
• Primes that remain prime through 3 iterations of function f(x) = 10x + 9.at n=40A023301
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 8.at n=35A031421
• Starting index of a string of 4 or more consecutive equal digits in decimal expansion of Pi.at n=16A049516
• Starting index of a string of exactly 4 consecutive equal digits in decimal expansion of Pi.at n=11A049520
• Row sums of array T as in A055215.at n=31A054405
• Smallest prime with digit sum n, or 0 if no such prime exists.at n=33A067180
• The smallest prime with a possible given digit sum.at n=22A067523
• a(n) is the smallest positive integer that cannot be obtained using at most n-1 of the integers {1, 2, ..., n} using each number at most once and the operators +, -, *, /.at n=8A071985
• Smallest prime whose digital sum is equal to the n-th composite number, or 0 if no such prime exists.at n=21A073867
• Starting positions of strings of three 9's in the decimal expansion of Pi.at n=15A083642
• Prime mean of 8 horizontal, vertical and main diagonal sums associated with primes in A094454.at n=21A094455
• Primes p such that q-p = 24, where q is the next prime after p.at n=29A098974
• Primes with digit sum = 34.at n=0A106769
• Smallest prime whose digital sum is equal to the n-th composite number not congruent to 0 (modulo 3).at n=11A111380
• a(n) is the largest prime < 10*a(n-1) for n > 1, with a(1) = 2.at n=4A124262
• Primes congruent to 22 mod 53.at n=35A142552
• Primes congruent to 53 mod 59.at n=34A142780