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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A083115 Palindromes in A083114.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 111, 121, 131, 141, 151, 161, 171, 191, 212, 222, 313, 1111, 1221, 1331, 2112, 3113, 11111, 11211, 11311, 11411, 11511, 11711, 12121, 12221, 13131, 21112, 21212, 31113, 111111, 112211, 121121
Offset: 1

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Author

Amarnath Murthy, Apr 23 2003

Keywords

Comments

Intersection of A117056 and A052382. - Jayanta Basu, May 15 2013

Crossrefs

Cf. A083114.

Programs

  • Mathematica
    id[n_]:=IntegerDigits[n]; palQ[n_]:=Reverse[x=id[n]]==x; t={}; Do[If[palQ[n] && (y=Times@@id[n])>0 && palQ[Plus@@id[n]] && palQ[y],AppendTo[t,n]],{n,125000}]; t (* Jayanta Basu, May 15 2013 *)
    spQ[n_]:=Module[{idn=IntegerDigits[n]},FreeQ[idn,0]&&AllTrue[ {n,Total[ idn],Times@@idn},PalindromeQ]]; Select[Range[125000],spQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jan 30 2021 *)
  • PARI
    ispal(n)=n=digits(n);for(i=1,#n\2,if(n[i]!=n[#n+1-i],return(0)));1
    is(n)=my(d=vecsort(digits(n)));d[1]&&ispal(sum(i=1,#d,d[i]))&&ispal(prod(i=1,#d,d[i]))&&ispal(n) \\ Charles R Greathouse IV, May 15 2013

Formula

a(n) >> 3^n. - Charles R Greathouse IV, May 15 2013
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