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 A329982 a(1) = 0, and for n > 0, a(n+1) = k^2 - a(n) where k is the number of terms equal to a(n) among the first n terms. 3
 0, 1, 0, 4, -3, 4, 0, 9, -8, 9, -5, 6, -5, 9, 0, 16, -15, 16, -12, 13, -12, 16, -7, 8, -7, 11, -10, 11, -7, 16, 0, 25, -24, 25, -21, 22, -21, 25, -16, 17, -16, 20, -19, 20, -16, 25, -9, 10, -9, 13, -9, 18, -17, 18, -14, 15, -14, 18, -9, 25, 0, 36, -35, 36, -32 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS In other words, for n > 0, a(n+1) = o(n)^2 - a(n) where o is the ordinal transform of the sequence. LINKS Rémy Sigrist, Table of n, a(n) for n = 1..10000 Rémy Sigrist, Scatterplot of the first 2^20 terms EXAMPLE The first terms, alongside their ordinal transform, are: n a(n) o(n) -- ---- ---- 1 0 1 2 1 1 3 0 2 4 4 1 5 -3 1 6 4 2 7 0 3 8 9 1 9 -8 1 10 9 2 PROG (PARI) for (n=1, #(a=vector(65)), print1 (a[n]=if (n>1, sum(k=1, n-1, a[k]==a[n-1])^2-a[n-1])", ")) CROSSREFS See A329981 for similar sequences. Sequence in context: A255257 A306769 A336031 * A243149 A048156 A070431 Adjacent sequences: A329979 A329980 A329981 * A329983 A329984 A329985 KEYWORD sign,look AUTHOR Rémy Sigrist, Nov 26 2019 STATUS approved

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Last modified September 16 14:25 EDT 2024. Contains 375976 sequences. (Running on oeis4.)