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 A278167 #10 Nov 14 2016 10:38:12 %S A278167 1,1,2,2,2,3,5,6,7,7,9,10,12,12,15,17,17,20,20,22,22,23,27,29,32,34, %T A278167 38,40,40,43,46,48,53,56,60,63,66,69,71,75,77,79,83,86,89,92,98,101, %U A278167 102,105,109,111,117,120,123,125,130,135,140,145,149,152,159,163,167,173,177,179,183,189,194,199,204,208,215,219,223,230,234 %N A278167 a(n) = number of primes encountered before reaching 0 when starting from k = ((n+1)^2)-1 and iterating map k -> k - A002828(k). %C A278167 a(n) = number of terms of A277888 less than (n+1)^2. %H A278167 Antti Karttunen, <a href="/A278167/b278167.txt">Table of n, a(n) for n = 1..10000</a> %F A278167 a(1) = A277487(1); for n > 1, a(n) = A277487(n) + a(n-1). %e A278167 For n=4, starting from k = ((4+1)^2)-1, and iterating k -> A255131(k), yields 24 -> 21 -> 18 -> 16 -> 15 -> 11 -> 8 -> 6 -> 3 before 0 is reached. Of these numbers only 11 and 3 are primes, thus a(4) = 2. %o A278167 (Scheme) (definec (A278167 n) (if (= 1 n) (A277487 n) (+ (A277487 n) (A278167 (- n 1))))) %Y A278167 Partial sums of A277487. %Y A278167 Cf. A002828, A255131, A278166, A278168, A277888. %K A278167 nonn %O A278167 1,3 %A A278167 _Antti Karttunen_, Nov 13 2016