Processing math: 7%

Problem #263

Subset Intersection

Let S be a set of size n. Let T_k be the set of all ordered k-tuples (A_1, A_2, A_3, A_4…...A_k) where A_i is a subset of S, such that A_1 ∪ A_2 ∪ A_3 ∪ A_4…...A_k = S.

Given n=2718281828 and k=3141592653, find the sum of |A_{1}∩ A_{2} ∩ A_{3} ∩ A_{4}……..∩ A_{k}|^2 for all k-tuples (A_1, A_2, A_3, A_4…...A_k) belonging to T_k. The answer can be huge, so compute it modulo 10^9+7.

Contributed by Yaswanth Chunduru

Solved by 11 users

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