177750

Appears in sequences

• Triangle T(n,k) read by rows, where T(n,k) = number of times the permanent of a real singular n X n (0,1)-matrix takes the value k, for n >= 2, 0 <= k <= n!.at n=51A089481
• a(0) = a(1) = 1; for n >= 2, a(n) = a(n-1) + a(n-2) - n if that number is positive and not already in the sequence, otherwise a(n) = a(n-1) + a(n-2) + n.at n=27A117821
• Smaller member of an infinitary amicable pair.at n=26A126169
• Smaller of bi-unitary amicable pair.at n=26A292980
• Lesser of tri-unitary amicable numbers pair: numbers (m, n) such that tsigma(m) = tsigma(n) = m + n, where tsigma(n) is the sum of the tri-unitary divisors of n (A324706).at n=19A324708