20547

Appears in sequences

• a(n) = integer nearest a(n-1)/(sqrt(7) - 2), where a(1) = 1.at n=22A024567
• Expansion of (1-x)/(1 - x - x^2 - 3*x^3 + 3*x^4).at n=17A052915
• 30 'Reverse and Add' steps are needed to reach a palindrome.at n=5A065319
• Number of ordered triples (i,j,k) with |i| + |j| + |k| <= n and gcd(i,j,k) <= 1.at n=26A100450
• Numbers whose arithmetic derivatives are a permutation of their digits.at n=31A225902
• G.f.: 1/(1 - x/(1+2*x - x^3/(1+2*x^2 - x^5/(1+2*x^3 - x^7/(1+2*x^4 - x^9/(1 - ...)))))), a continued fraction.at n=69A275761
• Number of sets of exactly six positive integers <= n having a square element sum.at n=22A281866
• Numbers of the form HMMSS with primes H < 24 and MM, SS < 60, for which the number of seconds after midnight, 3600*H+60*MM+SS, is also prime.at n=14A295011
• Expansion of e.g.f. exp(exp(3*x) - exp(2*x)).at n=6A355381
• Expansion of 1/((1 - x - x^4)^2 - 4*x^5).at n=16A375283