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 A204474 Number of 10-element subsets that can be chosen from {1,2,...,10*n} having element sum 50*n+5. 2
 0, 1, 5448, 517971, 10388788, 97809616, 587267282, 2615047418, 9408671330, 28851490163, 78132541528, 191563698893, 432971108530, 914435915008, 1823570327812, 3461969170632, 6297974185728, 11037428544793, 18716682230144, 30822735206253, 49446074607790 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS a(n) is the number of partitions of 50*n+5 into 10 distinct parts <= 10*n. LINKS Alois P. Heinz, Table of n, a(n) for n = 0..1000 FORMULA G.f.: (2934*x^31 +348266*x^30 +6597024*x^29 +49734090*x^28 +217728951*x^27 +667463008*x^26 +1585348242*x^25 +3103463874*x^24 +5228487221*x^23 +7832917054*x^22 +10700328447*x^21 +13574603633*x^20 +16172892190*x^19 +18185529447*x^18 +19316679453*x^17 +19372433191*x^16 +18342644114*x^15 +16405735056*x^14 +13851791136*x^13 +10991882803*x^12 +8111849599*x^11 +5470428985*x^10 +3289797304*x^9 +1708913237*x^8 +735273835*x^7 +246947710*x^6 +58833425*x^5 +8344142*x^4 +496184*x^3 +5444*x^2+x) / ((x^2+1)*(x^6+x^3+1)*(x^6+x^5+x^4+x^3+x^2+x+1)*(x+1)^2*(x^2+x+1)^3*(x-1)^10). EXAMPLE a(2) = 5448 because there are 5448 10-element subsets that can be chosen from {1,2,...,20} having element sum 105: {1,2,3,4,5,16,17,18,19,20},{1,2,3,4,6,15,17,18,19,20}, ..., {6,7,8,9,10,11,12,13,14,15}. MAPLE a:= n-> (Matrix(32, (i, j)-> `if`(i=j-1, 1, `if`(i=32, [-1, 4, -5, 2, -2, 2, 5, -7, 2, -2, -1, 9, -6, -1, 1, -7, 14, -7, 1, -1, -6, 9, -1, -2, 2, -7, 5, 2, -2, 2, -5, 4][j], 0)))^n. <<0, 1, 5448, 517971, 10388788, 97809616, 587267282, 2615047418, 9408671330, 28851490163, 78132541528, 191563698893, 432971108530, 914435915008, 1823570327812, 3461969170632, 6297974185728, 11037428544793, 18716682230144, 30822735206253, 49446074607790, 77472474506552, 118820782200294, 178734513401148, 264135920159882, 384052079868415, 550123481245484, 777206553792057, 1084082600833512, 1494286652957642, 2037070858360564, 2748518169368740>>)[1, 1]: seq(a(n), n=0..50); CROSSREFS Column k=10 of A204459. Sequence in context: A222696 A125016 A234157 * A251052 A259514 A217255 Adjacent sequences: A204471 A204472 A204473 * A204475 A204476 A204477 KEYWORD nonn,easy AUTHOR Alois P. Heinz, Jan 16 2012 STATUS approved

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Last modified June 6 01:24 EDT 2023. Contains 363138 sequences. (Running on oeis4.)