A123137 a(n) = a(n-1)^2 + Sum of the digits of a(n-1), with a(1)=1.

1, 2, 6, 42, 1770, 3132915, 9815156397249, 96337295102457969494768070, 9280874427658072275134580545332124401295103091525032, 86134630141957550628261532252390058231417831318795074704890644033088478051503964693639295413423482601219

Offset

1,2

Links

Table of n, a(n) for n=1..10.

A. Frank & P. Jacqueroux, International Contest, 2001. Item 28

Example

a(5) = 42^2 + (4 + 2) = 1770

Mathematica

NestList[#^2+Total[IntegerDigits[#]]&, 1, 10] (* Harvey P. Dale, Nov 30 2011 *)

Prog

(PARI) a=1; for(n=1, 11, print1(a, ", "); sda=eval(Vec(Str(a))); a=a^2+sum(i=1, length(sda), sda[i]))

Crossrefs

Sequence in context: A115961 A355042 A367132 * A014117 A242927 A054377

Adjacent sequences: A123134 A123135 A123136 * A123138 A123139 A123140

Keyword

nonn,base

Author

Herman Jamke (hermanjamke(AT)fastmail.fm), Sep 30 2006

Status

approved