26078

Appears in sequences

• Numbers k such that (k, sigma(k)) lies on a circle with integral radius centered at the origin, i.e., k^2 + sigma(k)^2 is a square.at n=26A066764
• Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-1111-1100 pattern in any orientation.at n=12A147477
• Expansion of (chi(q) / chi^3(q^3))^2 in powers of q where chi() is a Ramanujan theta function.at n=37A164614
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 475", based on the 5-celled von Neumann neighborhood.at n=32A272449