|
%I #38 Mar 04 2023 08:59:46
%S 0,9,23,30,35,49,58,73,94,113
%N A puzzle by Ron Hoeflin.
%C In November 1987, an editor at the Astrophysical Journal wrote to _N. J. A. Sloane_ with three sequences whose explanation was not known to her. She said: "As to the pedigree of these sequences, not much is known. But they are US in origin, and /not/ Hungarian". One of the three was the number-theoretical sequence A007468. The other two are now A199714 and A199715.
%C Looking at the first differences (9, 14, 7, 5, 14, 9, 15, 21), one may notice that the last three terms are 3*(3, 5, 7), and the relation 9 = 14 - 5 seems to appear twice. Taking the second differences yields (5, -7, -2, 9, -5, 6, 6), where similar relations 5 - 7 = -2 and 7 + 2 = 9 can be seen. - _M. F. Hasler_, Mar 14 2018
%C This puzzle occurs on a trial test by Ron Hoeflin for his Titan Test. It is question 13 on Trial Test F. Link is below. The sequence differences are the alphabetical positions (a is 1, b is 2, etc.) of the letters in the word "ingenious." Since s is 19, the next term is 94 + 19 = 113. Then the sequence ends. - _Chris Cole_, Mar 03 2023
%H Ron Hoeflin, <a href="https://megasociety.org/noesis/18_noetic.pdf">Noesis 18</a>, p. 6.
%K nonn,fini,full
%O 1,2
%A _N. J. A. Sloane_, Nov 09 2011
%E a(10) from _Chris Cole_, Mar 03 2023
|
