Shesha

In the Bhagavata Purana Shesha is named Sankarshana, the tamasic energy of Lord Narayana himself, and is said to live deep within the inner layers of patala, where there are many serpents with gems on their heads and where Sankarshana is the ruler. He is said to live since before the creation of the universe. When the universe is towards its end, he creates 11 rudras from him to destroy the universe for a new one to be created.

http://lordofsnake.blogspot.com/search/label/Shesha

Number of Rudraksha beads in Rudraksha Mala

1. Wearing a Rudraksha mala consisting of 100 beads helps a person to attain salvation.
2. A Rudraksha mala consisting of 108 beads brings success and helps in accomplishing all kinds of works. Wearing this mala even benefits the descendants of a person.
3. A person holdinga  Rudraksha mala consisting of 140 beads is blessed with courage, power and good health.
4. A Rudraksha mala consisting of 32 beads brings wealth, prosperity and longevity to a person.
5. A Rudraksha mala consisting of 26 beads should be worn on the forehead.
6. A Rudraksha mala consisting of  50 beads should be worn in the neck.
7. A Rudraksha mala consiting of 15 beads is beneficial for tantra-mantra and attainment of siddhis.
8. A Rudraksha mala consisting of 16 beads should be worn in the hands.
9. It is beneficial to wear a Rudraksha mala consisting of 12 beads on the wrist.
10. A person achieves virtue by holding a Rudraksha mala made with 50, 108 or 27 beads and chanting mantras while holding it.

http://www.yatan-ayur.com.au/online-store/yoga-and-meditation/general-information/using-a-mala
https://www.google.com/search?q=Rudrayamala