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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A276241 Let n have j digits {d_j, d_(j-1), ..., d_2, d_1}. Sequence lists numbers n such that R(n) = d_j^b_j + d_(j-1)^b_(j-1) + ... + d_2^b_2 + d_1^b_1 for some permutation {b_j, b_(j-1), ..., b_2, b_1} of the digits, where R(n) is the digits reverse of n.

Original entry on oeis.org

1, 10, 4631, 5343, 5514, 5534, 6134, 36471, 45130, 51287, 52684, 52736, 85200, 176623, 216793, 218256, 272438, 325786, 357691, 396711, 479615, 512870, 577631, 582356, 593736, 627461, 647481, 654731, 716623, 726639, 759356, 858324, 917462, 925731, 945630, 1075785
Offset: 1

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Author

Paolo P. Lava, Aug 25 2016

Keywords

Comments

0^0 is not admitted.

Examples

			One of the permutations of {4,6,3,1} is {3,4,1,6} and 4^3 + 6^4 + 3^1 + 1^6 = 1364 = R(4631).
		

Crossrefs

Programs

  • Maple
    with(combinat):  R:=proc(w) local x, y, z; x:=w; y:=0; for z from 1 to ilog10(x)+1 do y:=10*y+(x mod 10); x:=trunc(x/10); od; y; end:
    P:= proc(q) local a,b,c,d,i,j,k,n,ok,x;
    for n from 1 to q do i:=R(n); x:=convert(n,base,10); d:=ilog10(n)+1; b:=permute(x,d); a:={}; ok:=1;
    for k from 1 to nops(x) do a:={op(a),x{d-k+1}}; od; for k from 1 to nops(b) do c:=0;
    for j from 1 to d do if a{j}=0 and b{k}{j}=0 then ok:=0; break; else c:=c+a{j}^b{k}{j}; fi; od;
    if ok=1 then if i=c then print(n); break; fi; fi; od; od;  end: P(10^12);
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