72581

Appears in sequences

• Strong pseudoprimes to base 22.at n=21A020248
• a(n) = n^4/2 - n^3 + 3*n^2/2 - n + 1 = (n^2 + 1)*(n^2 - 2*n + 2)/2.at n=20A058919
• a(n) = a(n-1)+ceiling(a(n-2)/2) with a(0)=0, a(1)=1.at n=36A064323
• Solutions k of the equation phi(k) = phi(k-1) + phi(k-2). Also known as Phibonacci numbers.at n=29A065557
• Composite numbers k such that phi(k) = phi(k-1) + phi(k-2).at n=6A065572
• a(n) = a(n-1) + a(n-2) - floor(a(n-2)/2), starting 2,1.at n=35A173497
• a(n) = p(n+3)-p(n+1), where p(n) = A238825(n).at n=13A238826
• Sum T(n,k) of the entries in the k-th last blocks of all set partitions of [n]; triangle T(n,k), n>=1, 1<=k<=n, read by rows.at n=40A286232
• Number of integer partitions of n with unimodal run-lengths.at n=47A332280