cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A355670 Numbers k such that A246600(k) < A000005(k).

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%I A355670 #13 Jan 20 2023 08:33:58
%S A355670 2,4,6,8,9,10,12,14,16,18,20,21,22,24,25,26,28,30,32,33,34,35,36,38,
%T A355670 39,40,42,44,45,46,48,49,50,52,54,55,56,57,58,60,62,64,65,66,68,69,70,
%U A355670 72,74,75,76,77,78,80,81,82,84,86,87,88,90,91,92,93,94,96
%N A355670 Numbers k such that A246600(k) < A000005(k).
%C A355670 Numbers k such that bitwise OR(k, d_1, d_2, ... d_m) > k where d_1, ..., d_m are the divisors of k.
%C A355670 Complement of A359080.
%C A355670 First 21 terms coincide with A336376.
%C A355670 A102554 is a subsequence;  this sequence contains 1, 135, 175, 243, 343, 351, 363, ... which are not in A102554.
%o A355670 (Python)
%o A355670 from itertools import count, islice
%o A355670 from operator import ior
%o A355670 from functools import reduce
%o A355670 from sympy import divisors
%o A355670 def A355670_gen(startvalue=1): # generator of terms >= startvalue
%o A355670     return filter(lambda n:n|reduce(ior,divisors(n,generator=True))>n,count(max(startvalue,1)))
%o A355670 A355670_list = list(islice(A355670_gen(), 20))
%Y A355670 Cf. A000005, A102553, A102554, A246600, A336375, A359080.
%K A355670 nonn,base
%O A355670 1,1
%A A355670 _Chai Wah Wu_, Dec 19 2022