This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A123137 a(n) = a(n-1)^2 + Sum of the digits of a(n-1), with a(1)=1. 0
 1, 2, 6, 42, 1770, 3132915, 9815156397249, 96337295102457969494768070, 9280874427658072275134580545332124401295103091525032, 86134630141957550628261532252390058231417831318795074704890644033088478051503964693639295413423482601219 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS 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: A152479 A250309 A115961 * 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 12 20:12 EST 2019. Contains 329961 sequences. (Running on oeis4.)