141421

Appears in sequences

• Decimal expansion of sqrt(2) truncated to n places.at n=5A011547
• Decimal expansion of sqrt(2) rounded to n places.at n=5A011548
• Sum{T(n-k,k)}, 0<=k<=[ n/2 ], T given by A026907.at n=17A026918
• a(n)/100000 gives sqrt(n) to 5 places after the decimal point.at n=1A027663
• Index of smallest triangular number with n digits.at n=10A068092
• Triangular number index of A077206(n).at n=10A077207
• a(n) = the largest integer whose square has n digits and first digit 1.at n=10A083377
• Numbers k such that k and k^2 use only the digits 1, 2, 4, 8 and 9.at n=34A137000
• Number of triangular numbers <= 10^n.at n=10A236043