S000983


Differences between terms in the n-th row of S000982.

230, 41, 287, 82, 279, 49, 148, 677, 148, 49, 279, 82, 287, 41, 230, 513, 1190, 764, 874, 891, 874, 764, 1190, 259, 599, 11129, 1344, 2859, 1344, 11129, 599, 2859, 15653, 21403, 80729, 32503, 10776, 12081, 20759, 11115, 20759, 12081, 10776, 76795, 72479

1

S000983

The first row ends with 513. It appears that all rows are symmetric — reading the same forwards and backwards - with an additional number. For example, the first row has 230, 41, 287,…, 287, 41, 230, 513.

T. D. Noe, Plot of 153 arrays

T. D. Noe, Table of 153 arrays

David W. Boyd, Greg Martin, and Mark Thom, Squarefree values of trinomial discriminants, LMS J. Comput. Math. 18 (1) (2015), p. 148-169

(Mma) t4 = {}; Do[s = Select[Range[2, p^2], Mod[PowerMod[#, #, p^2] + (-1)^# PowerMod[# - 1, # - 1, p^2], p^2] == 0 &]; If[Length[s] > 0, AppendTo[s, p^2 - p + s[[1]]]; AppendTo[t4, Differences[s]]], {p, Prime[Range[PrimePi[1000]]]}]; t4

Cf. A238194, S000980-S000984.

nonn,hard

T. D. Noe, Mar 18 2017

© Tony D Noe 2014-2017