Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #21 Sep 19 2024 14:42:12
%S 1,2,3,4,5,6,7,8,9,12,45,56,90,567,3456
%N 7-smooth numbers (A002473) using digits in increasing order. 9 is followed by a zero.
%C No more terms < 10^1000. Probably no more terms. - _David Wasserman_, Feb 10 2005
%e 567 is a member as 567 = 3^4*7.
%o (PARI) hcn(n) = while (!(n%2), n \=2); while (!(n%3), n \=3); while (!(n%5), n \=5); while (!(n%7), n \=7); n == 1;
%o for (i = 0, 1000, for (j = 1, 9, my(n = sum(k = j, i + j, (k%10)*10^(i + j - k))); if (hcn(n), print1(n, ", ")))); /* _David Wasserman_, Feb 10 2005 */
%Y Intersection of A002473 and A059043.
%Y Cf. A085890.
%K base,nonn
%O 1,2
%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jul 10 2003
%E 3456 from _David Wasserman_, Feb 10 2005