136929

Appears in sequences

• Wieferich numbers (1): n > 1 such that 2^A000010(n) == 1 (mod n^2).at n=16A077816
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 0, 0), (0, 0, 1), (1, -1, 1), (1, 1, -1)}.at n=11A148406
• Numbers n > 1 such that 2^m == 1 (mod n^2), where m = A002326((n-1)/2).at n=12A265630
• Numbers n > 1 such that 2^lambda(n) == 1 (mod n^2), where lambda(n) is the Carmichael lambda function (A002322).at n=13A291961
• a(n) = Sum_{j=1..n} Sum_{k=1..n} phi(j*k).at n=32A372633