A383079 Number of n-digit positive integers where all pairs of consecutive digits have a difference of at least 7.
9, 9, 22, 48, 109, 244, 549, 1233, 2771, 6226, 13990, 31435, 70634, 158713, 356625, 801329, 1800570, 4045844, 9090929, 20427132, 45899349, 103134901, 231742019, 520719590, 1170046298, 2629070167, 5907467042, 13273957953, 29826312781, 67019116473, 150590587774
Offset: 1
Links
- Index entries for linear recurrences with constant coefficients, signature (2,1,-1).
Formula
G.f.: x*(4*x^3-5*x^2-9*x+9)/(x^3-x^2-2*x+1). - Alois P. Heinz, Apr 15 2025
Extensions
More terms from Alois P. Heinz, Apr 15 2025