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 A257233 #12 Jan 10 2025 01:17:20 %S A257233 1,7,6,6,4,2,6,2,4,6,4,2,4,2,6,2,4,6,2,4,4,2,4,2,2,4,6,6,4,2,2,2,2,2, %T A257233 4,4,2,6,2,2,2,6,2,4,2,4,4,2,4,2,6,2,2,2,6,6,2,2,2,2,4,2,2,2,2,4 %N A257233 Multiplicity sequence for the alternating row sums of triangle A257232. %C A257233 The sequence of alternating row sums of A257232 gives one times 1, seven times 2, 6 times 3, six times 4, four times 5, etc., in this order. %C A257233 Is a(n) = A067970(n-1), n>=3 ? - _R. J. Mathar_, Apr 24 2015 %F A257233 The number m appears a(m) times in the sequence of row sums of triangle A257232 for m = 1, 2, ..., that is in sum(((-1)^(k-1))*(n - (k-1) - [isprime(k)]), k = 1..n) with [isprime(k)] = A010051(k) for n >= 1. %Y A257233 Cf. A257232. %K A257233 nonn,easy %O A257233 1,2 %A A257233 _Wolfdieter Lang_, Apr 19 2015