cp's OEIS Frontend

From Bruno Berselli, May 09 2013: (Start)

a(n) - 2*a(n-1), for n>0, gives A019928 (after 1);

a(n) - 5*a(n-1), for n>0, gives A016311 (after 1);

a(n) - 7*a(n-1), for n>0, gives A016297 (after 1);

a(n) - 8*a(n-1), for n>0, gives A016296 (after 1);

a(n) - 7*a(n-1) + 10*a(n-2), for n>1, gives A016177 (after 15);

a(n) - 9*a(n-1) + 14*a(n-2), for n>1, gives A016162 (after 13);

a(n) - 10*a(n-1) + 16*a(n-2), for n>1, gives A016161 (after 12);

a(n) - 12*a(n-1) + 35*a(n-2), for n>1, gives A016131 (after 10);

a(n) - 13*a(n-1) + 40*a(n-2), for n>1, gives A016130 (after 9);

a(n) - 15*a(n-1) + 56*a(n-2), for n>1, gives A016127 (after 7);

a(n) - 20*a(n-1) +131*a(n-2) -280*a(n-3), for n>2, gives A000079 (after 4);

a(n) - 17*a(n-1) +86*a(n-2) -112*a(n-3), for n>2, gives A000351 (after 25);

a(n) - 15*a(n-1) +66*a(n-2) -80*a(n-3), for n>2, gives A000420 (after 49);

a(n) - 14*a(n-1) +59*a(n-2) -70*a(n-3), for n>2, gives A001018 (after 64),

and naturally: a(n) - 22*a(n-1) + 171*a(n-2) - 542*a(n-3) + 560*a(n-4), for n>3, gives 0 (see Harvey P. Dale in Formula lines). (End)

Number of ways to assign truth values to n quaternary conjunctions connected by disjunctions such that the proposition is true. For example, a(2) = 31, since for the proposition '(a & b & c & d) v (e & f & g & h)' there are 31 assignments that make the proposition true. - Ori Milstein, Dec 31 2022

Equivalently, the number of length-n words over the alphabet {0,1,..,15} with at least one letter = 15. - Joerg Arndt, Jan 01 2023

The next term (a(7)) has 103 digits. - Harvey P. Dale, Jul 05 2023