100121

Appears in sequences

• Let N =149162536496481100121441691962252562893243614..., the concatenation of the squares. a(n) is the n-digit number formed from the digits of N starting from the {n(n-1)/2 +1}th digit. Omit any leading zeros.at n=5A066551
• n^2 concatenated with (n+1)^2.at n=10A246973
• Number of times the digit 9 appears in the first 10^n decimal digits of sqrt(2), sometimes called Pythagoras's constant, counting after the decimal point.at n=5A322650