A102111 Iccanobirt numbers (1 of 15): a(n) = a(n-1) + a(n-2) + R(a(n-3)), where R is the digit reversal function A004086.
0, 0, 1, 1, 2, 4, 7, 13, 24, 44, 99, 185, 328, 612, 1521, 2956, 4693, 8900, 20185, 33049, 53332, 144483, 291848, 459666, 1135955, 2443813, 4246722, 12285846, 19716010, 34278280, 118852511, 154192582, 281332336, 550783729, 1117407516, 2301424427
Offset: 0
Programs
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Magma
a:=[0,0,1];[n le 3 select a[n] else Self(n-1) + Self(n-2) + Seqint(Reverse(Intseq(Self(n-3)))):n in [1..36]]; // Marius A. Burtea, Oct 23 2019
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Maple
read("transforms") ; A102111 := proc(n) option remember; if n <= 2 then return op(n+1,[0,0,1]) ; else return procname(n-1)+procname(n-2)+digrev(procname(n-3)) ; end if; end proc: seq(A102111(n),n=0..20) ; # R. J. Mathar, Nov 17 2012 -
Mathematica
R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=a[n-1]+a[n-2]+R[a[n-3]];Table[a[n], {n, 0, 40}] nxt[{a_,b_,c_}]:={b,c,IntegerReverse[a]+b+c}; NestList[nxt,{0,0,1},40][[;;,1]] (* Harvey P. Dale, Jul 18 2023 *) -
Python
def R(n): n_str = str(n) reversedn_str = n_str[::-1] reversedn = int(reversedn_str) return reversedn def A(n): if n == 0: return 0 elif n == 1: return 0 elif n == 2: return 1 elif n >= 3: return A(n-1)+A(n-2)+R(A(n-3)) for i in range(0,20): print(A(i)) # Dylan Delgado, Oct 23 2019
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