131144

Appears in sequences

• Numbers k such that phi(k) = phi(k+1).at n=39A001274
• Numbers k such that the multiplicative group of residues prime to k, M_k, is isomorphic to M_{k+1}.at n=9A003276
• Numbers k such that 2*10^k + 7*R_k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=20A056702
• A number n is included in the sequence if and only if the n-th integer from among those positive integers which are coprime to n+1 = the (n+1)-st integer from among those positive integers which are coprime to n.at n=14A139766
• Positive integers with the same number of 1s in base 10 and base 2.at n=32A153115
• Number of (n+2) X (5+2) 0..1 arrays with no 3 x 3 subblock diagonal sum less than the antidiagonal sum or central row sum less than the central column sum.at n=14A258891