Word counts for 2of12inf.txt, along with word "power":
============================
WORDS           COMBINATIONS
len:number      k:number
----------------------------
2: 62           6: 736281
3: 642          5: 142506
4: 2546         4: 23751
5: 5122         3: 3276
6: 8303         2: 351
7: 11571        1: 26
8: 12687        0: 1
============================

Expected hits: 12687*1 + 11571*26 + 8303*351 + 5122*3276 + 2546*23751 + 642*142506 + 62*736281
 = 217615878
Counted hits (with filtering):
 = 217615878