Search: id:A028307 Results 1-1 of 1 results found. %I A028307 %S A028307 1,3,8,20,43,98,212,465,1000,2144,4497,9504,19872,41455,85356, %T A028307 178630,363467,757085,1541998,3183600,6515066,13357593,27432649, %U A028307 55914902,114683858,233517515,478061719,972479046,1986013932 %N A028307 Form a triangle with n numbers in top row; all other numbers are the sum of their parents. E.g.: 4 1 2 7; 5 3 9; 8 12; 20. The numbers must be positive and distinct and the final number is to be minimized. Sequence gives final number. %C A028307 Suggested by Problem 401 of the All-Soviet-Union Mathematical Competitions 1961-1986. Two different links are available for this collection. %H A028307 Mauro Fiorentini, Further comments %H A028307 Vladimir A. Pertsel (voldemar(AT)wiscon.weizmann.ac.il), Problems of the All-Soviet-Union Mathematical Competitions 1961-1986 %e A028307 Solutions for n=1,2,... are 1; 1 2; 2 1 4; 4 1 2 7; 7 2 1 4 6; 8 6 1 3 2 10... %Y A028307 Sequence in context: A143785 A135565 A139488 this_sequence A027298 A000236 A109327 %Y A028307 Adjacent sequences: A028304 A028305 A028306 this_sequence A028308 A028309 A028310 %K A028307 nonn,nice %O A028307 1,2 %A A028307 Mauro Fiorentini (mfiorentini(AT)etnoteam.it) %E A028307 More terms from the author, Jul 03, 2001 Search completed in 0.001 seconds