A058973 First integer reached in A058972.

1, 2, 3, 2, 4, 2, 5, 9, 2, 4, 8, 8, 9, 9, 10, 8, 8, 11, 2, 2, 12, 2, 13, 13, 14, 15, 4, 16, 2, 17, 4, 35, 19, 8, 23, 9, 8, 22, 25, 2, 26, 25, 2, 2, 24, 28, 8, 10, 4, 29, 2, 26, 29, 2, 2, 35, 33, 6, 2, 38, 33, 33, 40, 2, 68, 4, 8, 44, 41, 8, 4, 46, 35, 43, 49, 50, 2, 42, 8, 40, 58, 4, 59, 43, 61

Offset: 1

Author

N. J. A. Sloane, Jan 14 2001

Keywords

• nonn
• easy

Examples

			A058972(1) = 3: f(3/1) = 3/3 = 1 = a(1);
A058972(2) = 9: f(9/1) = 8/4 = 2 = a(2);
A058972(3) = 15: f(15/1) = 15/5 = 3 = a(3);
A058972(4) = 24: f(24/1) = 6/3 = 2 = a(4).
		

Links

• P. Schogt, The Wild Number Problem: math or fiction?, arXiv preprint arXiv:1211.6583 [math.HO], 2012. - From _N. J. A. Sloane_, Jan 03 2013

Crossrefs

Cf. A058972.

Programs

PARI

f2(p,q) = (sigma(p+q)-p-q)/numdiv(p+q);
f1(r) = f2(numerator(r), denominator(r));
loop(list) = {my(v=Vecrev(list)); for (i=2, #v, if (v[i] == v[1], return(1)););}
ff(n) = {my(ok=0, m=f2(n,1), list=List()); while(denominator(m) != 1, m = f1(m); listput(list, m); if (loop(list), return (0));); return(m);}
lista(nn) = {for (n=1, nn, my(x=ff(n)); if (x, print1(x, ", ")););} \\ Michel Marcus, Feb 09 2022

Extensions

Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 22 2003