78541

Properties

Appears in sequences

• Numbers k such that k^2 contains only digits {1,6,8}.at n=7A053908
• Noncomposite numbers in the western ray of the Ulam spiral as oriented on the March 1964 cover of Scientific American.at n=20A168025
• Primes p at which phi(p-1)/(p-1) reaches a new minimum, where phi is Euler's totient function.at n=7A241196
• Centered 11-gonal (or hendecagonal) primes.at n=18A262344
• Primes p such that p-2, p^2-2 and p^3-2 are all prime.at n=13A270972
• Centered 22-gonal primes.at n=35A276262
• G.f.: Product_{k>=1} (1 + x^(k*(k+1)/2)) / (1 - x^k).at n=36A280421
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + n*b(n), where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=17A296294
• Numbers n such that both n-1 and n are nonsquares and the least positive solutions to the Pell equations x1^2 - n*y1^2 =1 and x0^2-(n-1)*y0^2 = 1 have a record for rho(n)=log(x1)/log(x0).at n=26A303604
• Numbers p such that p, 2p-1, 3p-2, 4p-3 are primes.at n=23A336059
• Prime numbersat n=7707