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 1-4 of 4 results.

A113177 Fully additive with a(p) = Fibonacci(p); If, for p prime, p^(m_{n,p}) is the highest power of p dividing n with m>=0, then a(n) = Sum_{p prime} F(p)*(m_{n,p}), where F(p) = p-th Fibonacci number.

Original entry on oeis.org

0, 1, 2, 2, 5, 3, 13, 3, 4, 6, 89, 4, 233, 14, 7, 4, 1597, 5, 4181, 7, 15, 90, 28657, 5, 10, 234, 6, 15, 514229, 8, 1346269, 5, 91, 1598, 18, 6, 24157817, 4182, 235, 8, 165580141, 16, 433494437, 91, 9, 28658, 2971215073, 6, 26, 11, 1599, 235, 53316291173, 7, 94
Offset: 1

Views

Author

Leroy Quet, Oct 16 2005

Keywords

Examples

			12 = 2^2 * 3^1, so a(12) = F(2)*2 + F(3)*1 = 2 + 2 = 4.
		

Crossrefs

Cf. A373586 (indices of even terms), A373587 (of odd terms), A374052 (of multiples of 3), A374206 (2-adic valuation), A374207 (3-adic valuation), A374208 (5-adic valuation), A374209 [A007895(a(n))], A374124 [a(n) mod 360].
Cf. A374106 [gcd(a(n), A328845(n))], A374112 [gcd(a(n), A276085(n))].
For other completely additive sequences see the cross-references in A001414.

Programs

  • Mathematica
    b[t_]:=Fibonacci[First[t]]Last[t] a[n_]:=Apply[Plus, Map[b, FactorInteger[n]]] (* Esa Peuha, Oct 26 2005 *)
  • PARI
    { for(n=1,100,f=factor(n);s=0;for(i=1,matsize(f)[1],s+=fibonacci(f[i,1])*f[i,2]);print1(s,",")) } \\ Lambert Klasen, Oct 26 2005
    
  • Sage
    [0]+[sum([fibonacci(x[0])*x[1] for x in factor(n)]) for n in range(2,56)] # Danny Rorabaugh, Apr 03 2015

Formula

Totally additive with a(p) = A000045(p).

Extensions

More terms from Esa Peuha (esa.peuha(AT)helsinki.fi) and Lambert Klasen (lambert.klasen(AT)gmx.net), Oct 26 2005
Prefixed the name with a more succinct form of the definition given in comments. - Antti Karttunen, Jul 08 2024

A374208 The 5-adic valuation of A113177(n), where A113177 is fully additive with a(p) = Fibonacci(p).

Original entry on oeis.org

0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1
Offset: 2

Views

Author

Antti Karttunen, Jul 01 2024

Keywords

Crossrefs

Programs

  • PARI
    A113177(n) = if(n<=1, 0, my(f=factor(n)); sum(i=1, #f~, f[i, 2]*fibonacci(f[i,1])));
    A374208(n) = valuation(A113177(n), 5);

Formula

a(n) = A112765(A113177(n)).

A374206 The 2-adic valuation of A113177(n), where A113177 is fully additive with a(p) = Fibonacci(p).

Original entry on oeis.org

0, 1, 1, 0, 0, 0, 0, 2, 1, 0, 2, 0, 1, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 3, 0, 0, 0, 1, 1, 1, 0, 1, 0, 3, 0, 4, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 4, 0, 1, 0, 0, 0, 1, 0, 1, 1, 2, 0, 0, 0, 0, 0, 0, 0, 1, 2, 0, 1, 2, 0, 0, 3, 1, 0, 0, 1, 1, 0, 2, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 2, 0, 6, 0, 2, 2, 1, 0, 3
Offset: 2

Views

Author

Antti Karttunen, Jul 01 2024

Keywords

Crossrefs

Cf. A007814, A113177, A373586 (gives the indices of nonzero terms here, after its initial 1), A373587 (gives the indices of 0's).

Programs

  • PARI
    A113177(n) = if(n<=1, 0, my(f=factor(n)); sum(i=1, #f~, f[i, 2]*fibonacci(f[i,1])));
    A374206(n) = valuation(A113177(n), 2);

Formula

a(n) = A007814(A113177(n)).

A374217 The 3-adic valuation of sopfr(n), where sopfr is the sum of prime factors with repetition, A001414.

Original entry on oeis.org

0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 2, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 2, 2, 0, 0, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 3, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 2
Offset: 2

Views

Author

Antti Karttunen, Jul 02 2024

Keywords

Crossrefs

Cf. A001414, A007949, A289142 (gives the indices of nonzero terms here, after its initial 1), A373371
Cf. also A374207, A374216.

Programs

Formula

a(n) = A007949(A001414(n)).
Showing 1-4 of 4 results.