cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A102124 Iccanobirt numbers (14 of 15): a(n) = R(R(a(n-1)) + R(a(n-2)) + a(n-3)), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 31, 42, 44, 99, 581, 823, 216, 1251, 6592, 3964, 98, 47311, 72451, 99862, 73698, 789881, 684873, 171146, 8359081, 2855313, 6626115, 92901661, 80528542, 25591874, 127303561, 518156392, 14745484, 711014964, 521206301
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Links

Crossrefs

Cf. A102111-A102125.

Programs

  • Maple
    R:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||n):
a:= proc(n) option remember; `if`(n<3, binomial(n, 2),
       R(R(a(n-1)) + R(a(n-2)) + a(n-3)) )
    end:
seq(a(n), n=0..50);  # Alois P. Heinz, Jun 18 2014
  • Mathematica
    R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[R[a[n-1]]+R[a[n-2]]+a[n-3]];Table[a[n], {n, 0, 40}]

Formula

a(n) = A004086(A102116(n)).

A102113 Iccanobirt numbers (3 of 15): a(n) = a(n-1) + R(a(n-2)) + R(a(n-3)), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 13, 24, 62, 135, 203, 760, 1593, 1962, 5980, 12622, 16208, 39724, 142606, 265660, 914694, 1587497, 2150478, 10594748, 27283111, 120773124, 216660897, 649176190, 1868619823, 2758358381, 6139199008, 11266906261
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Links

Crossrefs

Cf. A102111-A102125.

Programs

  • Maple
    R:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||n):
a:= proc(n) option remember; `if`(n<3, binomial(n, 2),
       a(n-1) + R(a(n-2)) + R(a(n-3)) )
    end:
seq(a(n), n=0..50);  # Alois P. Heinz, Jun 18 2014
  • 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]+R[a[n-2]]+R[a[n-3]];Table[a[n], {n, 0, 40}]
nxt[{a1_,a2_,a3_}]:={a2,a3,a3+FromDigits[Reverse[IntegerDigits[ a1]]]+ FromDigits[ Reverse[ IntegerDigits[a2]]]}; Transpose[NestList[nxt,{0,0,1},40]][[1]] (* Harvey P. Dale, Oct 17 2012 *)
nxt[{a_,b_,c_}]:={b,c,c+IntegerReverse[b]+IntegerReverse[a]}; NestList[ nxt,{0,0,1},40][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 10 2016 *)

Formula

A004086(a(n)) = A102121(n).

A102115 Iccanobirt numbers (5 of 15): a(n) = R(a(n-1)) + a(n-2) + R(a(n-3)), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 13, 42, 44, 117, 779, 1138, 9801, 3204, 22135, 57415, 77633, 144214, 541549, 1123036, 7257201, 3095708, 21636315, 55486847, 104580673, 482935860, 247988412, 1073911003, 3317721397, 9220077878, 15106615327, 89503015162
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Links

Crossrefs

Cf. A102111-A102125.

Programs

  • Mathematica
    R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[a[n-1]]+a[n-2]+R[a[n-3]];Table[a[n], {n, 0, 40}]
nxt[{a_,b_,c_}]:={b,c,Total[FromDigits/@Reverse/@IntegerDigits[ {a,c}]]+b}; Transpose[NestList[nxt,{0,0,1},35]][[1]] (* Harvey P. Dale, Dec 19 2011 *)

Formula

A004086(a(n)) = A102123(n).

A102116 Iccanobirt numbers (6 of 15): a(n) = R(a(n-1)) + R(a(n-2)) + a(n-3), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 13, 42, 62, 63, 104, 499, 1458, 9639, 18409, 101308, 903221, 943819, 1141966, 8512981, 9527388, 11871383, 55668051, 62931854, 72771964, 148399704, 517843422, 705114520, 398159926, 1173206822, 3621090124, 6895084900
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Links

Crossrefs

Cf. A102111-A102125.

Programs

  • Mathematica
    R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[a[n-1]]+R[a[n-2]]+a[n-3];Table[a[n], {n, 0, 40}]
nxt[{a_,b_,c_}]:={b,c,FromDigits[Reverse[IntegerDigits[c]]]+ FromDigits[ Reverse[ IntegerDigits[b]]]+a}; Transpose[NestList[nxt,{0,0,1},40]][[1]] (* Harvey P. Dale, Oct 10 2014 *)

Formula

A004086(a(n)) = A102124(n).

A102117 Iccanobirt numbers (7 of 15): a(n) = R(a(n-1)) + R(a(n-2)) + R(a(n-3)), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 13, 42, 62, 81, 68, 130, 135, 648, 1408, 9418, 17036, 79261, 87517, 150946, 736926, 1350266, 7899219, 16380155, 70858879, 162124155, 704415429, 1573821475, 7217219419, 15814925285, 73143352729, 160127403115
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Links

Crossrefs

Cf. A102111-A102125.

Programs

  • Maple
    rev:= proc(n) local i, L;
L:= convert(n,base, 10);
add(L[-i]*10^(i-1),i=1..nops(L))
end proc:
A[0]:= 0: A[1]:= 0: A[2]:= 1:
RA[0]:=0: RA[1]:= 0: RA[2]:= 1:
for n from 3 to 100 do
  A[n]:= RA[n-1]+RA[n-2]+RA[n-3];
  RA[n]:= rev(A[n]);
od:
seq(A[n],n=0..100); # Robert Israel, Aug 04 2016
  • Mathematica
    R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[a[n-1]]+R[a[n-2]]+R[a[n-3]];Table[a[n], {n, 0, 40}]
nxt[{a_,b_,c_}]:={b,c,Total[IntegerReverse/@{a,b,c}]}; Transpose[ NestList[ nxt,{0,0,1},40]][[1]] (* The program uses the IntegerReverse function from Mathematica version 10 *) (* Harvey P. Dale, Nov 28 2015 *)

Formula

A004086(a(n)) = A102125(n).

A102114 Iccanobirt numbers (4 of 15): a(n) = R(a(n-1)) + a(n-2) + a(n-3), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 13, 42, 44, 99, 185, 724, 711, 1026, 7636, 8104, 12680, 24361, 37126, 99214, 102786, 823541, 347328, 1750070, 1871440, 2539179, 13340862, 31214950, 21821254, 89768624, 95723002, 131622637, 921717757, 985062768
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Crossrefs

Cf. A102111-A102125.

Programs

  • Mathematica
    R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[a[n-1]]+a[n-2]+a[n-3];Table[a[n], {n, 0, 40}]
nxt[{a_,b_,c_}]:={b,c,FromDigits[Reverse[IntegerDigits[c]]]+b+a}; Transpose[NestList[nxt,{0,0,1},40]][[1]]  (* Harvey P. Dale, May 30 2012 *)

Formula

A004086(a(n)) = A102122(n).

A102119 Iccanobirt numbers (9 of 15): a(n) = R(a(n-1) + a(n-2) + R(a(n-3))), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 31, 24, 26, 36, 401, 994, 8541, 9369, 90481, 803101, 122309, 918349, 6691411, 1892158, 8837259, 38317811, 15086655, 45813926, 46917727, 407993841, 224348715, 25411507, 629951893, 2286023711, 6507846892, 9250302919
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Crossrefs

Cf. A102111-A102125.

Programs

  • Mathematica
    R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[a[n-1]+a[n-2]+R[a[n-3]]];Table[a[n], {n, 0, 40}]

Formula

a(n) = A004086(A102111(n)).

A102120 Iccanobirt numbers (10 of 15): a(n) = R(a(n-1) + R(a(n-2)) + a(n-3)), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 31, 24, 44, 711, 977, 8311, 1089, 4023, 53122, 51475, 33677, 412441, 945145, 6303211, 1027527, 8075903, 51363612, 74868455, 376085401, 68539284, 214889742, 927862936, 2360934421, 2982905123, 1968515515, 8282454457
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Crossrefs

Cf. A102111-A102125.

Programs

  • Mathematica
    R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[a[n-1]+R[a[n-2]]+a[n-3]];Table[a[n], {n, 0, 40}]
nxt[{a_, b_, c_}] := {b, c, IntegerReverse[c + IntegerReverse[b] + a]}; NestList[nxt,{0,0,1},40][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Oct 30 2017 *)

Formula

a(n) = A004086(A102112(n)).

A102121 Iccanobirt numbers (11 of 15): a(n) = R(a(n-1) + R(a(n-2)) + R(a(n-3))), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 31, 24, 44, 99, 581, 427, 117, 6201, 6367, 4018, 8621, 16342, 41752, 18376, 15486, 185801, 336123, 551315, 925189, 7799571, 5524929, 5346628, 6800461, 15116342, 36822052, 98232826, 48616741, 398264631, 406948574
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Crossrefs

Cf. A102111-A102125.

Programs

  • Mathematica
    R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[a[n-1]+R[a[n-2]]+R[a[n-3]]];Table[a[n], {n, 0, 40}]
nxt[{a_,b_,c_}]:={b,c,IntegerReverse[c+IntegerReverse[b]+IntegerReverse[a]]}; NestList[ nxt,{0,0,1},40][[;;,1]] (* Harvey P. Dale, Mar 23 2023 *)

Formula

a(n) = A004086(A102113(n)).

A102122 Iccanobirt numbers (12 of 15): a(n) = R(R(a(n-1)) + a(n-2) + a(n-3)), where R is the digit reversal function A004086.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 7, 31, 42, 26, 531, 302, 67, 909, 8721, 4522, 48811, 72152, 6487, 908821, 844702, 6572211, 9726782, 29139201, 58129562, 86185456, 139627251, 949140792, 656458225, 9962261161, 6171227123, 20114953831, 68392496992
Offset: 0

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

Comments

Digit reversal variation of tribonacci numbers A000073.
Inspired by Iccanobif numbers: A001129, A014258-A014260.

Crossrefs

Cf. A102111-A102125.

Programs

  • Mathematica
    R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[R[a[n-1]]+a[n-2]+a[n-3]];Table[a[n], {n, 0, 40}]
nxt[{a_,b_,c_}]:={b,c,IntegerReverse[IntegerReverse[c]+b+a]}; NestList[nxt,{0,0,1},40][[;;,1]] (* Harvey P. Dale, Sep 10 2024 *)

Formula

a(n) = A004086(A102114(n)).
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