22265

Appears in sequences

• Multiples of Euler numbers.at n=3A002438
• E.g.f.: (sin x + cos 2x) / cos 3x.at n=6A007286
• Expansion of e.g.f.: 1/cos(tan(x)) (even-indexed coefficients only).at n=4A009010
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 15.at n=16A031603
• Gaps of 2 in sequence A038593 (lower terms).at n=20A038643
• a(n) = (n+5)^3 - n^3.at n=36A038867
• a(n) = (3^n+1) * (3^(n+1)+1) / 8.at n=5A051406
• Inverse Euler transform of 1, 1, 3, 8, 23, ... (A050535).at n=10A076865
• Number of ordered quadruples (i,j,k,l) in range [0..n] satisfying i == j (mod 2), j == k (mod 3) and k == l (mod 4).at n=26A115523
• Pentagonal numbers (A000326) whose digit reversal is a semiprime (A001358).at n=36A115709
• a(n) is the first pentagonal number that is nontrivially the sum of two pentagonal numbers of the type P(p) + P(p+n) (we always have P(k) = P(0) + P(k)).at n=30A133312
• Pentagonal numbers (A000326) which are the sum of 2 other positive pentagonal numbers.at n=28A136117
• a(n) = 46*n^2 + 1.at n=22A158632
• a(n) = 13*n^2 - 16*n + 5.at n=42A202141
• a(n) = Im((1-I)^(1-n)*A_{n, 3}(I)) where A_{n, k}(x) are the generalized Eulerian polynomials.at n=6A225147
• Pentagonal numbers which are the arithmetic mean of two consecutive primes.at n=17A234531
• a(n) = Sum_{k=0..n} binomial(n,k) * (1 + 3^k)^k.at n=3A244004
• g_n(16) where g is the weak Goodstein function defined in A266202.at n=20A271992
• Triangle of integers related to generalized Markov numbers, read by rows.at n=16A357870
• Pentagonal numbers which are products of three distinct primes.at n=26A381650