Search: id:A007586 Results 1-1 of 1 results found. %I A007586 M4835 %S A007586 0,1,12,42,100,195,336,532,792,1125,1540,2046,2652,3367,4200, %T A007586 5160,6256,7497,8892,10450,12180,14091,16192,18492,21000, %U A007586 23725,26676,29862,33292,36975,40920,45136,49632,54417,59500 %N A007586 11-gonal (or hendecagonal) pyramidal numbers: n(n+1)(3n-2)/2. %D A007586 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A007586 A. H. Beiler, Recreations in the Theory of Numbers, Dover, NY, 1964, p. 194. %F A007586 G.f.: x*(1+8*x)/(1-x)^4. %F A007586 Starting with 1 equals binomial transform of [1, 11, 19, 9, 0, 0, 0,...]. - Gary W. Adamson (qntmpkt(AT)yahoo.com), Nov 02 2007 %p A007586 restart: a:=n->sum(sum(k, j=3..n), k=0..n): seq(a(n), n=1..53):b:=n-> sum(sum(n, j=1..n), k=0..n): seq(a(n), n=1..53):c:=b+a:seq(c(n), n=0..35); [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Aug 24 2008] %p A007586 a:=n->add(binomial(n,2)+add(n, j=3..n),j=2..n):seq(a(n), n=1..40); [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Aug 27 2008] %Y A007586 Cf. A051682. %Y A007586 Cf. A093644 ((9, 1) Pascal, column m=3). %Y A007586 Sequence in context: A005901 A090554 A009948 this_sequence A122973 A074356 A088826 %Y A007586 Adjacent sequences: A007583 A007584 A007585 this_sequence A007587 A007588 A007589 %K A007586 nonn,easy,nice %O A007586 0,3 %A A007586 N. J. A. Sloane (njas(AT)research.att.com), R. K. Guy. Search completed in 0.001 seconds