185745

Appears in sequences

• Numbers k such that phi(k) is equal to A008473(k-1).at n=17A039780
• Triangular numbers whose digit reversal is also a triangular number.at n=26A061455
• Non-palindromic triangular numbers whose reverse is a triangular number with the same number of digits.at n=4A066528
• Triangular numbers whose reverse is also triangular.at n=17A066569
• Nonpalindromic triangular numbers whose digit reversal is also a triangular number (possibly with fewer digits).at n=12A069673
• Partial sums of dodecahedral numbers (A006566).at n=20A116689
• a(n) = m*(m+1)/2, where m = floor(n^(5/2)).at n=12A185542
• a(n) = binomial(F(n), 2) where F(n) = A000045(n).at n=15A191797