A171943 To get a(n+1), add to a(n) the product of the two closest digits to the comma printed before a(n); start with a(1)=a(2)=1.

1, 1, 2, 4, 12, 16, 18, 24, 40, 56, 56, 86, 134, 140, 144, 144, 148, 152, 160, 162, 162, 164, 166, 170, 176, 176, 182, 188, 190, 198, 198, 206, 222, 234, 238, 246, 262, 274, 278, 286, 302, 320, 326, 326, 344, 362, 374, 380, 392, 392, 398, 404

Offset

1,3

Comments

a(n+1) = a(n) + prod(the least significant digit of a(n-1), the most significant digit of a(n)).

From Zak Seidov, Oct 28 2010: (Start)

Starting with a(57701) all terms = 500040.

Apparently the sequence ends with constant terms for any initial terms a(1),a(2). (End)

Links

Table of n, a(n) for n=1..52.

Eric Angelini, Add to a(n) a product of digits

Eric Angelini, Add to a(n) a product of digits [Cached copy, with permission]

Crossrefs

Sequence in context: A082458 A230770 A224703 * A225748 A358231 A114064

Adjacent sequences: A171940 A171941 A171942 * A171944 A171945 A171946

Keyword

nonn,base

Author

Eric Angelini, Sep 25 2010

Status

approved