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.

Showing 1-2 of 2 results.

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

Views

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

A266280 Terms in A083115 that are the smallest members of equivalence classes generated by permutation of digits.

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, 11111, 11211, 11311, 11411, 11511, 11711, 12121, 12221, 13131, 111111, 112211, 1111111, 1112111, 1113111, 1115111, 1121211, 1131311, 11111111, 111111111
Offset: 1

Views

Author

Chai Wah Wu, Dec 27 2015

Keywords

Comments

Subsequence of A083115. Intersection of A083114 and A266140.
Differs from A083115 first at n=27.

Crossrefs

Showing 1-2 of 2 results.