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 1-3 of 3 results.

A353630 Arithmetic derivative of primorial base exp-function, reduced modulo 4.

Original entry on oeis.org

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

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Author

Antti Karttunen, May 01 2022

Keywords

Crossrefs

Cf. A010873, A166486 (parity of terms), A276086, A327860, A328572, A353493, A353640.
Cf. A353631, A353632 (bisections).
Cf. also A353486.

Programs

  • PARI
    A353630(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= (p^e); s += (e/p); n = n\p; p = nextprime(1+p)); ((s*m)%4); };

Formula

a(n) = A010873(A327860(n)).
a(n) = A353493(A276086(n)).
a(n) = A010873(A328572(n)*A353640(n)). [Note that all terms of A328572 are odd]

A353632 Even bisection of A353630: Arithmetic derivative of primorial base exp-function, reduced modulo 4, computed for even numbers.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 01 2022

Keywords

Crossrefs

Even bisection of A353630. A353631 gives the odd bisection.
Cf. also A353487, A353642.

Programs

  • PARI
    A353630(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= (p^e); s += (e/p); n = n\p; p = nextprime(1+p)); ((s*m)%4); };
    A353632(n) = A353630(n+n);

Formula

a(n) = A353630(2*n) = A010873(A327860(2*n)).
A000035(a(n)) = A000035(n).

A353641 Odd bisection of A353640.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 01 2022

Keywords

Crossrefs

Programs

  • PARI
    A353640(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= p^(e>0); s += (e/p); n = n\p; p = nextprime(1+p)); ((s*m)%4); };
    A353641(n) = A353640(n+n+1);

Formula

a(n) = A353640(2*n+1) = A010873(A342002(2*n+1)).
Showing 1-3 of 3 results.