1,2

Until the early part of the twentieth century 1 was regarded as a prime (cf. A008578).

"The problem of constructing magic squares with prime numbers only was first discussed by myself in The Weekly Dispatch for Jul 22 1900 and Aug 05 1900; but during the last three or four years it has received great attention from American mathematicians. First, they have sought to form these squares with the smallest possible constants.

"Thus the first nine prime numbers, 1 to 23 inclusive, sum to 99, which (being divisible by 3) is theoretically a suitable series; yet it has been demonstrated that the smallest possible constant is 111, and the required series as follows: 1,7,13,31,37,43,61,67,73." - Dudeney

H. E. Dudeney, Amusements in Mathematics, Nelson, London, 1917, page 125.

Harvey Heinz, Prime Magic Squares

Index entries for sequences related to magic squares

The square is [ 43 1 67 / 61 37 13 / 7 73 31 ].

Cf. A008578, A073350, A073502.

Sequence in context: A133325 A063583 A065764 this_sequence A040084 A046139 A023243

Adjacent sequences: A073470 A073471 A073472 this_sequence A073474 A073475 A073476

nonn,fini,full

Lee Sallows (Sallows(AT)psych.kun.nl), Aug 27 2002