1,1

A134072 = {1, 31, 431, 7431, 117431, 18117431, 2918117431, 472918117431, 76472918117431, 12376472918117431, 19912376472918117431, ...} = Concatenate Lucas numbers in reverse order. Indices of prime terms in A134072 are {2, 3, 5, 11, ...}.

Eric Weisstein, Link to a section of The World of Mathematics. Lucas Number

Eric Weisstein, Link to a section of The World of Mathematics. Smarandache Sequences.

a(1) = A134072(2) = 31.

a(2) = A134072(3) = 431.

a(3) = A134072(5) = 117431.

Cf. A000204 = Lucas numbers. Cf. A130774 = Concatenate Lucas numbers. Cf. A019523 = Concatenate Fibonacci numbers. Cf. A038399 = Concatenate first n nonzero Fibonacci numbers in reverse order. Cf. A134072 = Concatenation of A000204 Lucas numbers (beginning at 1) in reverse order. Cf. A134069 = Primes in A038399. Cf. A134070 = Primes in A130774.

Sequence in context: A068672 A089561 A134072 this_sequence A010836 A022723 A084234

Adjacent sequences: A134068 A134069 A134070 this_sequence A134072 A134073 A134074

hard,more,nonn

Alexander Adamchuk (alex(AT)kolmogorov.com), Oct 06 2007