The number 7 curiously relates to
H. P. Blavatsky and the Theosophical Society.
Lucifer was first published in 1887, and 1887 is the sum of 17 hundreds, 17 tens, and 17 units; H. P. B. lived at 17 Lansdowne Road, and 17 Avenue Road; Lucifer was published at 7 Duke Street; 7 volumes were completed at her death; Colonel Olcott first met her at 7 Beckman Street, and later at 71 Broadway, New York. Anna Kingsford was elected president first of the London T. S. Lodge on 7th January 1883; Isis Unveiled was published in 1877, and the Third volume of the Secret Doctrine was published in 1897, after her death.
The numerology on this is beyond bizarre, especially after Christine Lagarde's recent statements on the magical power of number 7. A 777, flight 17, goes down on 7/17, of 2 (x7) 14, which is 17 years exactly after its first flight on 7.17.97. It is 133 (adds to 7) days since the other 777, 370, went down on 3/7 / 2x(7)14