Find n | Java program to find the value at n - th place in the given sequence ; Definition of findNumber function ; Finding x from equation n = x ( x + 1 ) / 2 + 1 ; Base of current block ; Value of n - th element ; Driver code
import java . io . * ; class GFG { static int findNumber ( int n ) { int x = ( int ) Math . floor ( ( - 1 + Math . sqrt ( 1 + 8 * n - 8 ) ) / 2 ) ; int base = ( x * ( x + 1 ) ) / 2 + 1 ; return n - base + 1 ; } public static void main ( String [ ] args ) { int n = 55 ; System . out . println ( findNumber ( n ) ) ; } }