Find a formula for the nth triangular number S2 = 12 3+ 19 n a i divisible by 5, ii even? b For what values of n is S,: c What is the smallest value of n for which S, is divisible by: i 29 two...

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Extracted text: Find a formula for the nth triangular number S2 = 12 3+ 19 n a i divisible by 5, ii even? b For what values of n is S,: c What is the smallest value of n for which S, is divisible by: i 29 two distinct primes, 35 vi three distinct primes, iv 38, 26, four distinct primes? vii V