A065411 Fibonacci numbers whose digits sum to a square.

0, 1, 13, 144, 806515533049393, 61305790721611591, 83621143489848422977, 6356306993006846248183, 155576970220531065681649693, 78569350599398894027251472817058687522

Offset

1,3

Links

Harry J. Smith, Table of n, a(n) for n = 1..50

Example

144 is in the sequence because (1) it is a Fibonacci number and (2) the sum of its digits 1 + 4 + 4 = 9 is a square.

Prog

(PARI) {m=200; print1(0, ", "); for(n=2, m, a=fibonacci(n); s=0; k=a; while(k>0, d=divrem(k, 10); k=d[1]; s=s+d[2]); if(issquare(s), print1(a, ", ")))} \\ Luc Stevens (lms022(AT)yahoo.com), Apr 15 2006
(PARI) SumD(x)= { local(s=0); while (x>9, s+=x-10*(x\10); x\=10); return(s + x) } { n=0; for (m=0, 10^9, if (m==2, next); f=fibonacci(m); if (issquare(SumD(f)), write("b065411.txt", n++, " ", f); if (n==50, return)) ) } \\ Harry J. Smith, Oct 18 2009

Crossrefs

Cf. A000045.

Sequence in context: A072351 A134489 A064525 * A354466 A038492 A270579

Adjacent sequences: A065408 A065409 A065410 * A065412 A065413 A065414

Keyword

base,nonn

Author

Jason Earls, Nov 22 2001

Extensions

Entry revised by N. J. A. Sloane, Jul 23 2006

Status

approved