This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A117725 #34 Jan 04 2024 09:41:37 %S A117725 1,2,3,5,8,11,12,21,111,113,131,311,1112,1115,1121,1124,1142,1151, %T A117725 1211,1214,1241,1412,1421,1511,2111,2114,2141,2411,4112,4121,4211, %U A117725 5111,11111,11137,11173,11222,11289,11298,11317,11371,11713,11731,11829,11892,11928 %N A117725 Zeroless numbers for which the sum of the digits and the product of the digits are both Fibonacci numbers. %H A117725 Alois P. Heinz, <a href="/A117725/b117725.txt">Table of n, a(n) for n = 1..10000</a> %H A117725 David A. Corneth, <a href="/A117725/a117725.gp.txt">PARI program</a> %e A117725 18192 is a term because the sum of its digits is 1+8+1+9+2 = 21, the product of its digits is 1*8*1*9*2 = 144 and both 21 and 144 are Fibonacci numbers. %t A117725 isFibonacci[x_]:=MemberQ[Array[Fibonacci,2x],x];DeleteCases[ParallelTable[If[And[isFibonacci[Times@@IntegerDigits[n]],isFibonacci[Total[IntegerDigits[n]]]],n,a],{n,1,15000}],a] (* _J.W.L. (Jan) Eerland_, Jan 03 2024 *) %o A117725 (PARI) isfib(n) = my(k=n^2); k+=(k+1)<<2; issquare(k) || issquare(k-8); \\ A000045 %o A117725 isok(k) = my(d=digits(k)); vecmin(d) && isfib(vecsum(d)) && isfib(vecprod(d)); \\ _Michel Marcus_, Jan 03 2024 %o A117725 (PARI) \\ See PARI program in links %Y A117725 Cf. A000045, A117774. %Y A117725 Subsequence of A028840, A028890 and of A052382. %K A117725 base,nonn %O A117725 1,2 %A A117725 Luc Stevens (lms022(AT)yahoo.com), Apr 13 2006 %E A117725 a(45) from _J.W.L. (Jan) Eerland_, Jan 03 2024 %E A117725 Name clarified by _Michel Marcus_, Jan 03 2024