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.

A092875 Aronson transform of the "evil" sequence (A001969).

Original entry on oeis.org

2, 3, 5, 7, 9, 11, 12, 13, 15, 16, 17, 18, 20, 21, 23, 24, 27, 29, 31, 33, 34, 35, 36, 39, 41, 42, 43, 44, 45, 47, 48, 49, 51, 53, 54, 57, 59, 61, 63, 64, 65, 66, 68, 71, 72, 73, 75, 77, 78, 79, 80, 81, 83, 85, 87, 88, 89, 91, 92, 93, 95, 97, 99, 101, 102, 105, 107, 108, 109
Offset: 1

Views

Author

Ferenc Adorjan (fadorjan(AT)freemail.hu)

Keywords

Comments

b(n) positive monotonic sequence is the Aronson transform of a(n) positive monotonic sequence if every member of a(n) satisfies the condition: "k is in b if and only if b(k) is in a", so that k must be the least such number.

Crossrefs

Programs

  • PARI
    {arons(v)= /* Returns the Aronson transform of v */ local(x=[],pv=1,px=1,n=1,i=0,k,l); l=matsize(v)[2];
    /*The initial terms: */ if(n0 if (i+1) is in v */ if(k==i,n+=1;if(pv<0,pv=abs(pv);while(pv>0,n+=1;pv=isin (n,v,l,pv))), px=isin(i+1,x,i,px);if(px>0,pv=-abs(pv);while (pv<0,n+=1;pv=isin(n,v,l,pv)), pv=abs(pv);while(pv>0,n+=1;pv=isin(n,v,l,pv)))); x=concat(x,n);i+=1);/*print(i);*/ return(x) }
    {isin(x,v,l,poi)= /*If x integer is in v monotonic vector of length l, the function returns a positive 'poi', else a negative one. (poi is pointer, used for acceleration. The last returned value is recommended in the input) */
    poi=abs(poi);if(poi==1&&x1,poi-=1);if(x<>v [poi],poi*=-1), if(x>v[poi], while(x>v[poi]&&poiv [poi],poi*=-1)));return(poi))}

A080746 Inverse Aronson transform of lower Wythoff sequence A000201.

Original entry on oeis.org

1, 4, 6, 7, 9, 10, 12, 14, 15, 17, 19, 20, 22, 23, 25, 27, 28, 30, 31, 33, 35, 36, 38, 40, 41, 43, 44, 46, 48, 49, 51, 53, 54, 56, 57, 59, 61, 62, 64, 65, 67, 69, 70, 72, 74, 75, 77, 78, 80, 82, 83, 85, 86, 88, 90, 91, 93, 95, 96, 98, 99
Offset: 1

Views

Author

Matthew Vandermast, Mar 08 2003

Keywords

Crossrefs

Union of A003622 and A035336, omitting 2. Cf. A000201, A080760.
Same as A026273 except for initial terms.

Formula

Consists of numbers [phi[phi*k]] (k >= 1) and [phi[phi^2*k]]-1 (k >= 2), where phi = (1+sqrt(5))/2. - N. J. A. Sloane, Mar 10 2003
Showing 1-2 of 2 results.