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 A256716 a(n) = n*(n+1)*(22*n-19)/6. 3
 0, 1, 25, 94, 230, 455, 791, 1260, 1884, 2685, 3685, 4906, 6370, 8099, 10115, 12440, 15096, 18105, 21489, 25270, 29470, 34111, 39215, 44804, 50900, 57525, 64701, 72450, 80794, 89755, 99355, 109616, 120560, 132209, 144585, 157710, 171606, 186295, 201799 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS This sequence is related to the tridecagonal numbers (A051865) by a(n) = n*A051865(n) - Sum_{i=0..n-1} A051865(i). REFERENCES E. Deza and M. M. Deza, Figurate numbers, World Scientific Publishing (2012), page 93 (22nd row of the table). LINKS Bruno Berselli, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1). FORMULA G.f.: x*(1 + 21*x)/(1 - x)^4. a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) with n>3, a(0)=0, a(1)=1, a(2)=25, a(3)=94. a(n) = Sum_{i=0..n-1} (n-i)*(22*i+1) for n>0. MATHEMATICA Table[n (n + 1) (22 n - 19)/6, {n, 0, 40}] PROG (PARI) vector(40, n, n--; n*(n+1)*(22*n-19)/6) (Sage) [n*(n+1)*(22*n-19)/6 for n in (0..40)] (MAGMA) [n*(n+1)*(22*n-19)/6: n in [0..40]]; CROSSREFS Partial sums of A051876. Cf. similar sequences listed in A237616. Cf. A051865. Sequence in context: A280297 A090659 A010013 * A063769 A099771 A266818 Adjacent sequences:  A256713 A256714 A256715 * A256717 A256718 A256719 KEYWORD nonn,easy AUTHOR Bruno Berselli, Apr 09 2015 STATUS approved

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Last modified August 11 03:22 EDT 2020. Contains 336421 sequences. (Running on oeis4.)