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 A230267 Coins left after packing 5 curves coins patterns into fountain of coins base n. 10
 1, 3, 2, 6, 7, 9, 12, 16, 17, 23, 26, 30, 35, 41, 44, 52, 57, 63, 70, 78, 83, 93, 100, 108, 117, 127, 134, 146, 155, 165, 176, 188, 197, 211, 222, 234, 247, 261, 272, 288, 301, 315, 330, 346, 359, 377, 392, 408, 425, 443 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Refer to arrangement same as A005169: "A fountain is formed by starting with a row of coins, then stacking additional coins on top so that each new coin touches two in the previous row". The 5 curves coins patterns consist of a part of circumference and forms continuous area. There is total 13 distinct patterns. I would like to call "5C4S" type as it cover 4 coins and symmetry. When packing 5C4S into fountain of coins base n, the total number of 5C4S is A001399, the coins left is a(n) and void is A230276. See illustration in links. LINKS Kival Ngaokrajang, Illustration of initial terms (U) FORMULA G.f.: x*(x^3 - 2*x^2 + 2*x + 1)/((1-x)*(1-x^2)*(1-x^3)) (conjectured). - Ralf Stephan, Oct 17 2013 PROG (Small Basic) a=1 d=2 For n = 1 To 100   If n+1 >= 3 Then     If Math.Remainder(n+1, 3)=math.Remainder(n+1, 6) Then       d2=1     Else       d2=Math.Remainder(n+1, 3)+math.Remainder(n+1, 6)*Math.Power(-1, math.Remainder(n+1, 2))     EndIf     d[n+1]=d[n]+d2   EndIf   a[n+1]=a[n]+d[n+1] TextWindow.Write(a[n]+", ") EndFor CROSSREFS Cf. A008795 (3-curves coins patterns), A074148, A229093, A229154 (4-curves coins patterns), A001399 (5-curves coins patterns), A229593 (6-curves coins patterns). Sequence in context: A026187 A026211 A021310 * A286226 A269852 A329691 Adjacent sequences:  A230264 A230265 A230266 * A230268 A230269 A230270 KEYWORD nonn AUTHOR Kival Ngaokrajang, Oct 15 2013 STATUS approved

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Last modified July 13 13:48 EDT 2020. Contains 335688 sequences. (Running on oeis4.)