187489

Appears in sequences

• a(n) = (11*n + 4)^2.at n=39A017438
• sigma(n)-n is a perfect square associated with A049226.at n=24A049228
• Powers of a prime lucky number (A031157) but excluding lucky numbers (A000959).at n=30A057609
• Numbers n such that sigma(d(n^3))==d(sigma(n^2)), where d(n) is the number of divisors of n.at n=31A063797
• Let k be the least integer such that n^2 + Sum_{m=1..k} m^2 is a perfect square, then a(n) is the resulting square.at n=18A065611
• A nonlinear recurrence of order 3: a(1)=a(2)=a(3)=1; a(n)=(a(n-1)+a(n-2))^2/a(n-3).at n=6A072882
• Unsigned member r=-6 of the family of Chebyshev sequences S_r(n) defined in A092184.at n=7A098306
• Squares of the form prime(k)*prime(k+1) + 2*prime(k+1).at n=22A108604
• Squares of the form 6p+7 for p prime (A110015) that are squares of a prime.at n=33A110586
• Squares without a 0 digit and whose sum of digits minus 1 and product of digits plus 1 are both squares.at n=1A139565
• Squares that becomes primes when prefixed with a 3.at n=34A167718
• Composite numbers with both 10 and -10 as primitive root.at n=19A218766
• Nontrivial prime powers (A025475) which are a sum of a smaller nontrivial prime power and a perfect cube.at n=16A226232
• Prime powers (p^k, p prime, k >= 1) such that k*p^k - 1 is also a power of a prime.at n=42A263581
• Composite numbers k such that tau(k^(k-1)) is a prime.at n=40A283549
• Numbers k such that concat(k, d(k)) and concat(d(k), k) are both prime, where d(k) is the number of divisors of k.at n=15A284643
• a(n) is the denominator of the square of the n-th Lagrange number.at n=10A382099