A132114 Multiply previous term by 7 and reverse.

1, 7, 94, 856, 2995, 56902, 413893, 1527982, 47859601, 702710533, 1373798194, 8537856169, 38139946795, 565726979662, 4367588800693, 15840612137503, 125269482488011, 770614773688678, 6470285143034935, 54544210069919254

Offset

1,2

Links

Vaclav Kotesovec, Table of n, a(n) for n = 1..1000

Vaclav Kotesovec, Plot of a(n)^(1/n) for n = 1..10000

Formula

a(n) = reverse(7 * a(n-1)) with a(1) = 1.

Example

a(4) = reverse(7 * a(3)) = reverse(7 * reverse(7 * a(2))) = reverse(7 * reverse(7 * reverse(7 * a(1)))) = reverse(7 * reverse(7 * reverse(7))) = reverse(7*94) = 856.

Prog

(PARI) seq(n)={my(a=vector(n)); a[1]=1; for(n=2, #a, a[n]=fromdigits(Vecrev(digits(a[n-1]*7)))); a} \\ Andrew Howroyd, Jan 02 2020
(Magma) f:=func<n|Seqint(Reverse(Intseq(7*n)))>; a:=[1]; for n in [2..20] do Append(~a, f(a[n-1]));  end for; a; // Marius A. Burtea, Jan 03 2020

Crossrefs

Cf. A036447 (*2), A163632 (*3), A132064 (*4), A045539 (*5), A132078 (*6), A132113 (*8), A133361 (*9).

Sequence in context: A109304 A134113 A071584 * A221384 A243679 A367162

Adjacent sequences: A132111 A132112 A132113 * A132115 A132116 A132117

Keyword

base,nonn

Author

Rachit Agrawal (rachit_agrawal(AT)daiict.ac.in), Oct 31 2007

Extensions

Name edited by Andrew Howroyd, Jan 02 2020

Status

approved