A306106 Numbers with digits in {0,1,2,3} such that every other digit is strictly less than its neighbors.

0, 1, 2, 3, 10, 20, 21, 30, 31, 32, 101, 102, 103, 201, 202, 203, 212, 213, 301, 302, 303, 312, 313, 323, 1010, 1020, 1021, 1030, 1031, 1032, 2010, 2020, 2021, 2030, 2031, 2032, 2120, 2121, 2130, 2131, 2132, 3010, 3020, 3021, 3030, 3031, 3032, 3120, 3121, 3130, 3131, 3132, 3230, 3231, 3232, 10101, 10102, 10103

Offset

1,3

Comments

Terms of A032859 written in base 4.

Links

Table of n, a(n) for n=1..58.

Formula

a(n) = A007090(A032859(n)).

Terms in A297147 having only digits < 4; intersection of A297147 and A007090.

Prog

(PARI) A(Nmax=100, K=3, A=[0..K], i=vector(2*K, i, max(1, i-K+1)), c(T, v)=apply(t->t+T, v))={for(n=0, oo, for(k=10, K*11, if(k%10<k\10, k%10|| i=concat(i, 1+#A); A=concat(A, c(k*10^n, A[i[K*n+k%10+1]..i[K*n+K+1]-1])); #A<Nmax||return(A))))}

Crossrefs

Cf. A306105 .. A306111 and A297147: analog for bases 3..9 and 10.

Cf. A032859 and A032858 .. A032865 for other bases 3..10.

Sequence in context: A122822 A295951 A083944 * A165550 A328780 A184261

Adjacent sequences: A306103 A306104 A306105 * A306107 A306108 A306109

Keyword

nonn,base

Author

M. F. Hasler, Oct 05 2018

Status

approved