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 A373674 #8 Aug 02 2024 05:21:35 %S A373674 5,9,11,13,17,19,23,25,27,29,32,37,41,43,47,49,53,59,61,64,67,71,73, %T A373674 79,81,83,89,97,101,103,107,109,113,121,125,128,131,137,139,149,151, %U A373674 157,163,167,169,173,179,181,191,193,197,199,211,223,227,229,233,239 %N A373674 Last element of each maximal run of powers of primes (including 1). %C A373674 A run of a sequence (in this case A000961) is an interval of positions at which consecutive terms differ by one. %C A373674 The first element of the same run is A373673. %C A373674 Consists of all powers of primes k such that k+1 is not a power of primes. %H A373674 Gus Wiseman, <a href="/A373403/a373403.txt">Four statistics for runs and antiruns of prime, nonprime, squarefree, and nonsquarefree numbers</a>. %e A373674 The maximal runs of powers of primes begin: %e A373674 1 2 3 4 5 %e A373674 7 8 9 %e A373674 11 %e A373674 13 %e A373674 16 17 %e A373674 19 %e A373674 23 %e A373674 25 %e A373674 27 %e A373674 29 %e A373674 31 32 %e A373674 37 %e A373674 41 %e A373674 43 %e A373674 47 %e A373674 49 %t A373674 pripow[n_]:=n==1||PrimePowerQ[n]; %t A373674 Max/@Split[Select[Range[nn],pripow],#1+1==#2&]//Most %Y A373674 For prime antiruns we have A001359, min A006512, length A027833. %Y A373674 For composite runs we have A006093, min A008864, length A176246. %Y A373674 For prime runs we have A067774, min A025584, length A251092 or A175632. %Y A373674 For squarefree runs we have A373415, min A072284, length A120992. %Y A373674 For nonsquarefree runs we have min A053806, length A053797. %Y A373674 For runs of prime-powers: %Y A373674 - length A174965 %Y A373674 - min A373673 %Y A373674 - max A373674 (this sequence) %Y A373674 - sum A373675 %Y A373674 For runs of non-prime-powers: %Y A373674 - length A110969 (firsts A373669, sorted A373670) %Y A373674 - min A373676 %Y A373674 - max A373677 %Y A373674 - sum A373678 %Y A373674 For antiruns of prime-powers: %Y A373674 - length A373671 %Y A373674 - min A120430 %Y A373674 - max A006549 %Y A373674 - sum A373576 %Y A373674 For antiruns of non-prime-powers: %Y A373674 - length A373672 %Y A373674 - min A373575 %Y A373674 - max A255346 %Y A373674 - sum A373679 %Y A373674 A000961 lists all powers of primes (A246655 if not including 1). %Y A373674 A025528 counts prime-powers up to n. %Y A373674 A057820 gives first differences of consecutive prime-powers, gaps A093555. %Y A373674 A361102 lists all non-prime-powers (A024619 if not including 1). %Y A373674 Cf. A000040, A005381, A007674, A014963, A068780, A068781, A073051, A373400. %K A373674 nonn %O A373674 1,1 %A A373674 _Gus Wiseman_, Jun 16 2024