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 A213837 Principal diagonal of the convolution array A213836. 4
 1, 13, 52, 134, 275, 491, 798, 1212, 1749, 2425, 3256, 4258, 5447, 6839, 8450, 10296, 12393, 14757, 17404, 20350, 23611, 27203, 31142, 35444, 40125, 45201, 50688, 56602, 62959, 69775, 77066, 84848, 93137 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Clark Kimberling, Table of n, a(n) for n = 1..1000 Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1). FORMULA a(n) = n*(5 - 15*n + 16*n^2)/6. a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). G.f.: f(x)/g(x), where f(x) = x*(1 + 9*x + 6*x^2) and g(x) = (1-x)^4. a(n) = n*A002412(n) - (n-1)*A002412(n-1). [Bruno Berselli, Dec 11 2012] a(n) = n*A000384(n) + sum( A000384(i), i=0..n-1 ). [Bruno Berselli, Dec 18 2013] MATHEMATICA (See A213836.) CROSSREFS Cf. A000384, A002412, A213836, A220084 (for a list of numbers of the form n*P(k,n)-(n-1)*P(k,n-1), where P(k,n) is the n-th k-gonal pyramidal number). Sequence in context: A183941 A022673 A152742 * A047903 A197790 A317467 Adjacent sequences: A213834 A213835 A213836 * A213838 A213839 A213840 KEYWORD nonn,easy AUTHOR Clark Kimberling, Jul 04 2012 STATUS approved

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Last modified June 5 18:09 EDT 2023. Contains 363138 sequences. (Running on oeis4.)