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 A053743 Sum of numbers in range 10*n to 10*n+9. 3
 45, 145, 245, 345, 445, 545, 645, 745, 845, 945, 1045, 1145, 1245, 1345, 1445, 1545, 1645, 1745, 1845, 1945, 2045, 2145, 2245, 2345, 2445, 2545, 2645, 2745, 2845, 2945, 3045, 3145, 3245, 3345, 3445, 3545, 3645, 3745, 3845, 3945, 4045, 4145, 4245, 4345 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Harvey P. Dale, Table of n, a(n) for n = 0..1000 Tanya Khovanova, Recursive Sequences Index entries for linear recurrences with constant coefficients, signature (2,-1). FORMULA a(n) = 100*n + 45. From Colin Barker, Jun 26 2012: (Start) a(n) = 2*a(n-1) - a(n-2). G.f.: 5*(9+11*x)/(1-x)^2. (End) E.g.f.: 5*(9 + 20*x)*exp(x). - G. C. Greubel, Sep 06 2019 EXAMPLE 45 = sum of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; 145 = sum of 10, 11, 12, 13, 14, 15, 16, 17, 18, 19. MAPLE seq(5*(20*n+9), n=0..50); # G. C. Greubel, Sep 06 2019 MATHEMATICA LinearRecurrence[{2, -1}, {45, 145}, 50] (* or *) 100*Range[50]-55 (* Harvey P. Dale, Feb 03 2019 *) PROG (PARI) vector(50, n, 5*(20*n -11)) \\ G. C. Greubel, Sep 06 2019 (MAGMA) [5*(20*n+9): n in [0..50]]; // G. C. Greubel, Sep 06 2019 (Sage) [5*(20*n+9) for n in (0..50)] # G. C. Greubel, Sep 06 2019 (GAP) List([0..50], n-> 5*(20*n+9)); # G. C. Greubel, Sep 06 2019 CROSSREFS Cf. A053741, A053742. Sequence in context: A156370 A044377 A044758 * A234336 A173371 A288669 Adjacent sequences:  A053740 A053741 A053742 * A053744 A053745 A053746 KEYWORD nonn,easy AUTHOR Odimar Fabeny, Feb 13 2000 EXTENSIONS More terms from James A. Sellers, Feb 22 2000 STATUS approved

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Last modified October 20 12:47 EDT 2019. Contains 328257 sequences. (Running on oeis4.)