S000959


Least positive number x that begins a string of exactly n composite numbers of the form x^2 + x + 41.

44, 40, 121, 161, 298, 611, 325, 1543, 3784, 2827, 1795, 1063, 8504, 7141, 21897, 5663, 21439, 20244, 9264, 40800, 22817, 51108, 37783, 47493, 135944, 129497, 100201, 216671, 303048, 235699, 170295, 444660, 355352, 323768, 167627, 704240, 1609791, 176955

1

S000959

Note that this sequence name differs in only one word, “exactly,” from S000958.

T. D. Noe, Plot of 100 terms

T. D. Noe, Table of 100 terms

Carlos Rivera, Puzzle 853: The Euler polynomial again

(Mma) (* using the t array from the program in S000958 *) Table[cnt = 0; x = t[[n]] - 1; While[True, x++; If[PrimeQ[x^2 + x + 41], If[cnt == n, Break[]]; cnt = 0, cnt++]]; x - cnt, {n, Length[t]}]

Cf. S000958.

nonn

T. D. Noe, Nov 04 2016

© Tony D Noe 2014-2016