A370486 - OEIS

%I #15 Feb 20 2024 08:24:29

%S 36363636362,45454545453,54545454544,63636363635,72727272726,

%T 81818181817,90909090908,428571428571428571427,571428571428571428570,

%U 714285714285714285713,857142857142857142856,363636363636363636363636363636362,454545454545454545454545454545453

%N Terms in A116260 that are not of the form 10^d-1.

%C Since 10^d-1 for d>0 are terms of A116260, this sequence only includes terms of A116260 not of this form to highlight these nontrivial terms.

%H Chai Wah Wu, <a href="/A370486/b370486.txt">Table of n, a(n) for n = 1..44</a>

%o (Python)

%o from itertools import count, islice

%o from sympy import sqrt_mod

%o def A370486_gen(): # generator of terms

%o     for j in count(0):

%o         b = 10**j

%o         a = b*10+1

%o         for k in sorted(sqrt_mod(0,a,all_roots=True)):

%o             if a*(b+4) <= k**2 < a*(a+3):

%o                 yield k-2

%o A370486_list = list(islice(A370486_gen(),20))

%Y Cf. A116260.

%K nonn,base

%O 1,1

%A _Chai Wah Wu_, Feb 19 2024