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.

Previous Showing 11-13 of 13 results.

A171205 G.f. satisfies: A(x) = (1 + x*A(2x))^5.

Original entry on oeis.org

1, 5, 60, 1410, 62505, 5284401, 868838010, 281703950040, 181448450339760, 232989133846286240, 597389845561440183360, 3061032714235774931187200, 31357237236616342838622807040, 642321739861948533960660029617920, 26312068694834430629292373404100369920, 2155589935049851254662487477552439610480640
Offset: 0

Views

Author

Paul D. Hanna, Dec 05 2009

Keywords

Crossrefs

Programs

  • Mathematica
    terms = 16; A[] = 0; Do[A[x] = (1 + x*A[2x])^5 + O[x]^terms // Normal, terms]; CoefficientList[A[x], x] (* Stefano Spezia, Apr 02 2025 *)
  • PARI
    {a(n)=local(A=1+x+x*O(x^n)); for(i=0, n, A=(1+x*subst(A, x, 2*x))^5); polcoeff(A, n)}

Formula

Self-convolution 5th power of A171204 where a(n) = A171204(n+1)/2^n for n>=0.

Extensions

a(14)-a(15) from Stefano Spezia, Apr 02 2025

A171207 G.f. satisfies: A(x) = (1 + x*A(2x))^6.

Original entry on oeis.org

1, 6, 87, 2468, 131799, 13400550, 2646848041, 1030386755856, 796631252763576, 1227659952939056640, 3777547269650299331856, 23228194648169000672639616, 285544368619000766118426358016, 7018967175754802830514246125923840, 345031382341287335424234252089128848384
Offset: 0

Views

Author

Paul D. Hanna, Dec 05 2009

Keywords

Crossrefs

Programs

  • Mathematica
    terms = 15; A[] = 0; Do[A[x] = (1+x*A[2x])^6 + O[x]^terms // Normal, terms]; CoefficientList[A[x], x] (* Stefano Spezia, Apr 02 2025 *)
  • PARI
    {a(n)=local(A=1+x+x*O(x^n)); for(i=0, n, A=(1+x*subst(A, x, 2*x))^6); polcoeff(A, n)}

Formula

Self-convolution 6th power of A171206 where a(n) = A171206(n+1)/2^n for n>=0.

Extensions

a(14) from Stefano Spezia, Apr 02 2025

A171209 G.f. satisfies: A(x) = (1 + x*A(2x))^7.

Original entry on oeis.org

1, 7, 119, 3955, 247093, 29355725, 6770018269, 3075928905505, 2774997766597238, 4989660046676105752, 17913062958150482828608, 128508635121001835101510976, 1843071985575998120371392747776, 52855626540938653363337299348546560, 3031270298538159379928340759759663584000
Offset: 0

Views

Author

Paul D. Hanna, Dec 05 2009

Keywords

Crossrefs

Programs

  • Mathematica
    terms = 15; A[] = 0; Do[A[x] = (1+x*A[2x])^7 + O[x]^terms // Normal, terms]; CoefficientList[A[x], x] (* Stefano Spezia, Apr 02 2025 *)
  • PARI
    {a(n)=local(A=1+x+x*O(x^n)); for(i=0, n, A=(1+x*subst(A, x, 2*x))^7); polcoeff(A, n)}

Formula

Self-convolution 7th power of A171208 where a(n) = A171208(n+1)/2^n for n>=0.

Extensions

a(13)-a(14) from Stefano Spezia, Apr 02 2025
Previous Showing 11-13 of 13 results.