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 11-12 of 12 results.

A090793 Minimal numbers n such that numerator(Bernoulli(2*n)/(2*n)) is different from numerator(Bernoulli(2*n)/(2*n*(2*n-r))) for some integer r and the first m irregular primes including irregularity index > 1.

Original entry on oeis.org

52, 80, 95, 134, 114, 141, 213, 187, 211, 274, 338, 312, 312, 292, 370, 350, 456, 486, 445, 502, 428, 465, 488, 591, 471, 540, 615, 558, 527, 513, 563, 636, 658, 659, 722, 583, 681, 789, 667, 602, 631, 632, 603, 902, 873, 626, 703, 785, 832, 670, 743, 764
Offset: 1

Views

Author

Cino Hilliard, Feb 16 2004

Keywords

Comments

Only even values of r are tested.

Crossrefs

Programs

  • PARI
    \ prestore some ireg primes in iprime[] bernmin(m) = { for(x=1,m, p=iprime[x]; forstep(r=2,p,2, n=r/2+p; n2=n+n; a = numerator(bernfrac(n2)/(n2)); \ A001067 b = numerator(a/(n2-r)); \ if(a <> b,print(r","n","a/b)) if(a <> b,print1(n",")) ) ) }

Formula

Given a = numerator(Bernoulli(2*n)/(2*n)) and b = numerator(a/(2*n-r)) for integer r positive or negative, then n>0 n = p + r/2 For every irregular prime p there is an r such that n is minimum.

A090800 r when numerator(Bernoulli(2*n)/(2*n)) and numerator(Bernoulli(2*n)/(2*n*(2*n-r))) are different and n is minimum for some integer r for the first i irregular primes. These include entries when the irregularity index > 1.

Original entry on oeis.org

30, 42, 56, 66, 22, 20, 128, 60, 108, 82, 162, 98, 82, 18, 154, 86, 290, 278, 184, 298, 98, 172, 198, 380, 124, 238, 364, 194, 128, 92, 192, 290, 334, 336, 398, 84, 268, 484, 220, 50, 88, 90, 20, 590, 520, 18, 172, 336, 426, 78, 224, 234, 240, 552, 46, 222, 406, 500
Offset: 2

Views

Author

Cino Hilliard, Feb 16 2004

Keywords

Comments

This is a generalization of the concept in A090495 and A090496. One can change the code below from p = iprime[x] to p = prime(x) and see that data for only irregular primes is generated.

Crossrefs

Programs

  • PARI
    \ prestore some ireg primes in iprime[] or use slower PARI BIF prime() bernmin(m) = { for(x=1,m, p=iprime[x]; forstep(r=2,p,2, n=r/2+p; n2=n+n; a = numerator(bernfrac(n2)/(n2)); \ A001067 b = numerator(a/(n2-r)); \ if(a <> b,print(r","n","a/b)) if(a <> b,print1(r",")) ) ) }

Formula

Given a = numerator(Bernoulli(2*n)/(2*n)) and b = numerator(a/(2*n-r)) for integer r positive or negative, then n>0 n = p + r/2. For every irregular prime p there is an r such that n is minimum.
Previous Showing 11-12 of 12 results.