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.
%I A375928 #7 Sep 13 2024 06:53:06 %S A375928 1,2,3,4,6,7,10,11,12,13,14,18,21,22,25,26,29,34,35,37,39,42,43,48,49, %T A375928 50,55,62,65,66,69,70,73,80,83,84,86,91,92,101,102,107,112,115,116, %U A375928 119,124,125,134,135,138,139,150,161,164,165,168,173,174,175,182 %N A375928 Positions of adjacent non-prime-powers (exclusive) differing by more than 1. %F A375928 The inclusive version is a(n+1) - 1. %e A375928 The non-prime-powers (exclusive) are 1, 6, 10, 12, 14, 15, 18, 20, ... which increase by more than 1 after positions 1, 2, 3, 4, 6, 7, ... %t A375928 ce=Select[Range[100],!PrimePowerQ[#]&]; %t A375928 Select[Range[Length[ce]-1],!ce[[#+1]]==ce[[#]]+1&] %Y A375928 For prime-powers inclusive (A000961) we have A376163, differences A373672. %Y A375928 For nonprime numbers (A002808) we have A014689, differences A046933. %Y A375928 First differences are A110969. %Y A375928 The complement is A375713. %Y A375928 For non-perfect-powers we have A375714, complement A375740. %Y A375928 The complement for prime-powers (exclusive) is A375734, differences A373671. %Y A375928 The complement for nonprime numbers is A375926, differences A373403. %Y A375928 A000040 lists the prime numbers, differences A001223. %Y A375928 A000961 lists prime-powers (inclusive), differences A057820. %Y A375928 A007916 lists non-perfect-powers, differences A375706. %Y A375928 A024619 lists non-prime-powers (inclusive), differences A375735. %Y A375928 A246655 lists prime-powers (exclusive), differences A174965. %Y A375928 A361102 lists non-prime-powers (exclusive), differences A375708. %Y A375928 Cf. A006549, A053289, A073783, A093555, A120430, A176246, A251092. %K A375928 nonn %O A375928 1,2 %A A375928 _Gus Wiseman_, Sep 12 2024