21055

Appears in sequences

• Times in hours,minutes and seconds (to the nearest second) at which the smoothly crossing minute and hour hands of an analog clock coincide, over a period of one complete 12-hour sweep of the hour hand.at n=2A120500
• Times in hours, minutes and seconds (to the nearest second) at which the hour and minute hands of an analog clock, if interchanged, continue to indicate some other albeit accurate times, over a complete 12-hour sweep for the slower hand. Leading zeros omitted.at n=26A121577
• a(1) = 1; thereafter a(n) is always the smallest integer > a(n-1) not leading to a contradiction, such that any five consecutive digits in the sequence sum up to a prime.at n=34A152605
• Number of nX2 0..2 arrays with rows and columns lexicographically nondecreasing and the instance counts of every value within one of each other.at n=15A201426
• Number of n X 3 0..1 arrays with no 1 equal to more than four of its king-move neighbors.at n=4A282311
• Number of nX5 0..1 arrays with no 1 equal to more than four of its king-move neighbors.at n=2A282313
• T(n,k)=Number of nXk 0..1 arrays with no 1 equal to more than four of its king-move neighbors.at n=23A282316
• T(n,k)=Number of nXk 0..1 arrays with no 1 equal to more than four of its king-move neighbors.at n=25A282316