Pentagram was not so much a magazine, but more like a newsletter. Subtitled "A Witchcraft Review", it was  just 4 pages. Published by The Witchcraft Research Association (WRA) Founded by Sybil Leek and Gerard Noel. Sybil was the first president, and then Doreen Valiente. Doreen obviously wrote most if not all of it although most of it is not credited. It sold for Two Shillings, though it was 'For Private Circulation Only'.

Doreen and Sybil should need no introduction, but you can read about them here: Sybil : https://en.wikipedia.org/wiki/Sybil_Leek and her Diary of a Witch. Doreen: https://en.wikipedia.org/wiki/Doreen_Valiente and her autobiography https://books.google.com/books/about/The_Rebirth_of_Witchcraft.html?id=llTqPgAACAAJ .

pentagram was published from 1964 through 1966. These rare items are the first 3 issues. presumably there 3 or more issues. If anyone has any of those, please let me know.