21852

Appears in sequences

• a(n) = (4^n + 20)/3.at n=8A156605
• a(n) = 1458*n - 18.at n=14A157508
• a(n) = n*prime(prime(n)) - prime(n).at n=30A230285
• Lengths of runs of the initial digits of semiprimes in decimal representation, cf. A239634.at n=39A239639
• Sum of numbers in the n-th antidiagonal of the reciprocity array of 0.at n=44A259574
• Counterexamples to a conjecture of Ramanujan about congruences related to the partition function.at n=36A340757
• Main diagonal of array in A358304, divided by 2.at n=37A358307