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.

A076072 Largest multiple of n that can be formed by using the digits of the next n numbers, or 0 if no such number exists.

This page as a plain text file.
%I A076072 #14 Jan 17 2020 10:41:23
%S A076072 1,32,654,97180,4321111115,987622111110,87654322222222,
%T A076072 9654333333332120,987544444443333210,98765555555444443210,
%U A076072 9876666666665555524130,988777777777776666543120,99998888888888877654321100
%N A076072 Largest multiple of n that can be formed by using the digits of the next n numbers, or 0 if no such number exists.
%C A076072 Conjecture: No entry is zero. (At least one multiple of n can be formed by using the digits of the next n numbers.)
%C A076072 "Next n numbers" means {1+n(n-1)/2,...,n(n+1)/2}. - _M. F. Hasler_, Jul 22 2011
%o A076072 (PARI) precperm(p)={ my(t); forstep(i=#p-1,1,-1, p[i]>p[i+1] && for( j=1, #t=vecsort(vecextract(p,2^#p-2^(i-1)),,4), t[j]<p[i] && return(concat([vecextract(p,2^(i-1)-1), [t[j]], vecextract(t,Str("^"j))])))); vecsort(p,,4)} /* generic function, could be simplified/optimized for here */
%o A076072 A076072(n)={ my(d=vecsort(Vec(concat(vector(n,i,Str(i+n*(n-1)/2)))),,4)); for( i=1, (#d)!, eval(concat(d))%n || break; d=precperm(d)); eval(concat(d))}  \\ _M. F. Hasler_, Jul 24 2011
%Y A076072 Cf. A076070, A076071, A076073, A080480, A192392.
%K A076072 base,nonn
%O A076072 1,2
%A A076072 _Amarnath Murthy_, Oct 05 2002
%E A076072 More terms from _David Wasserman_, Mar 23 2005