|
%I #2 Mar 30 2012 17:27:41
%S 4,9,17,40,74,54,151,120,307,312,199,408,356,424,912,1032,1217,840,
%T 1872,423,1608,2518,1588,1920,1230,2112,3713,1560,5208,2832,3952,2872,
%U 3192,3288,3432,8400,5738,4080,4272,4512,6288,8280,8520,5232,5352,3672,8892
%N Local maxima of A053707 (first differences of A025475, powers of a prime but not prime).
%C A053707(k) for k = 1 is a term iff A053707(k) >= A053707(k+1); A053707(k) for k > 1 is a term iff A053707(k-1) < A053707(k) and A053707(k) >= A053707(k+1).
%C A088366 gives the corresponding indices. Local minima of A053707 are in A088363.
%e The first six terms of A053707 are 3,4,1,7,9,2, hence A053707(2) = 4 is the first and A053707(5) = 9 is the second local maximum of A053707.
%o (PARI) {m=1; k=0; for(n=2,250000,if(matsize(factor(n))[1]==1&&factor(n)[1,2]>1,d=n-m; if((k<2||b<c)&&(!k<1&&d<=c),print1(c,",")); k++; m=n; b=c; c=d))}
%Y Cf. A025475, A053707, A088366, A088363.
%K nonn
%O 1,1
%A _Klaus Brockhaus_, Sep 27 2003
|
